I ran a similar setup in a 40 breeder for 2.5 years and never saw any significant results. I used a fine lava rock around and under the UGF, then a layer of kitty litter and Florite red. Capped it with fine gravel coarse sand mix, and lots of plants. My nitrates were always the same as my other tanks. Thanks for sharing.
@@UncleSmileys.Aquariums Thanks so much for the answer, I've started and abandoned the hobby so many times because I love the hobby, but it's always the weekly water changes that make me hit the wall. Sometimes I have a really busy time and the weekend work just kills me... I dont remember frequent water changes as a child (Under gravel filter days) and I think I could sustain it again if Anoxic could space out that need.
I don’t do water changes on 4 of my big tanks and I don’t have 3 inches of sand on them. I think it’s all about balance. Plants filters and etc. I have very aggressive cichlids and iridescent sharks. I noticed that high nitrates equals low kh.
Wastewater treatment process analyst here. I appreciate you running this test so methodically and documenting every step of the way. However, I think one important limitation to your experiment is that facultative heterotrophic bacteria require a carbon source to denitrify in anoxic conditions. Most wastewater treatment plants use something in the way of methanol, but in an aquarium, the organic matter from fish waste, food, plant material, etc. would serve as your carbon source. That carbon is your limiting factor here, and without it, denitrification cannot take place.
You could consider dosing sugar as a carbon source and see what your nitrates look like in a few more weeks. I would hate to see those five months go to waste without that carbon.
Christian, you beat me to it. In the UK, around 1983, we had a denitrification system on sale which required a dose of methanol every week. It was a bit fiddly to maintain, but it worked. It never caught on, though.
Interesting. This has got to be the number one comment here. Thanks for mentioning this. Those of us who use the anoxic method have fish and fish food in the tank. There are a lot of factors going on. To assume that the anoxic doesn't work and it is just the plants is to make the same mistake as to assume that the plants don't work and the anoxic filter is the only factor.
So all he has proven if anything is adding pure ammonia to a fishless tank for a few months doesn't make denitrification occur in his particular setup.
I was happy to see you roll with this test. I use anoxic setups for my four freshwater tanks and they run so so well. But as you've pointed out, I am one of those who has planted aquariums so no way my use of anoxic setups will test true denitrification. I still believe in the system and they are excellent for planted aquarium hobbyists. But I can't say first hand I've ever used anoxic as a solo method. No arguments from me my friend. Now, plant that tank and drop in some cool fish that aren't rainbows hahaha. Enjoy
Thanks for sharing and taking the time to experiment! I have a 30g planted tank and use an anoxic filtration setup with an undergravel filter. Above it I have a mix of SafeTsorb and Brightwell Aquatics FlorinBase Laterin Subtrat VF in mesh bags sandwiched between layers of Eco Complete. I use a cannister filter to polish the water on top of that. I only run the undergravel filter at night. Personally, I never worried or even thought about the "denitrification" part of such a setup because, to your point, the plants take care of that. For me the benefit is the algae reduction and a way of using steady liquid fertilizer dosing to constantly recharge my substrate without having to use (or eventually replace) an active aquasoil. Being that I have 29 different plant species in the tank and they are growing out of control, I think, for my purposes, it's been a success. Seeing your results, though, should give pause to anyone considering this setup as a way of reducing water changes in high bio-load / low plant tanks. I think you might be onto something by questioning an anoxic filtration system's ability of achieving natural denitrification in smaller water volume setups compared to the larger pond/lake level environments.
Brilliant idea for a video, Bentley! If I'm honest, I was expecting the results you got. It would have been fascinating to find the nitrates had dropped significantly. Realistically, though, I would assume that it would have to be a far deeper substrate with far more organic build up down there.
Well, it came out similar to when I tried it a few years ago. I was enamored with this idea when I was a struggling college student and could barely afford my hobby, because it mimicked how substrate works in lake and river bottoms. So, I really wanted to replicate it at home and set up a similar process in my sump tank. Ultimately, I was never able to show it did anything. I had a few anecdotal wins. But looking at it critically: my tank was filtered by the abundant plant life in the display, and the duck weed I kept floating in the sump tank. This process is well documented in nature and lab tests, we know it can work, and some industrial processes purposely mimic it. However, it's very difficult to establish it correctly in a home aquarium. And I remember posting similar criticism on Kevin's channel a few years ago. It’s not a question of “does this process work?” It does, we know it does. Rather the question is “can we replicate this process in a small & closed system?” Something like a 50-100-gallon aquarium. And the most common answer seems to be “not really”. Or at least “not well”. You could try carbon dosing it next, to see if you could accelerate and grow the bacterial population which would then have a higher respiration demand and thus hopefully denitrify. That's the next step. N probably isn't your limiting rate. Nor is P likely. Your limiting rate will either be a micronutrient (which is also unlikely) or simply C. What you probably ran into is your bacterial colony isn’t large enough to use up all the free oxygen in the sediment. So, it never needs the O from NO2 or NO3 in respiration. Which results in zero denitrification. These target bacteria are facultative, meaning they can swap around being aerobic or anaerobic. Denitrification is a less efficient process, so they won’t do it if there is enough free oxygen in their surrounding environment (the sediment). You need the colony to be large enough to use up all the free oxygen first. And like most who attempt this, you don’t have the carrying capacity for the bacteria to hit that population size. Regularly dosing a small amount of vinegar or vodka can jump start it and increase their population density. But, that's hard to regulate and is a moving target. When I tried it, I found it was very difficult to get a consistent result. And when you dose a carbon source to a tank, you’re more likely to grow heterotrophic aerobic bacteria instead. That is the direction the marine side of the hobby went with carbon dosing. Instead of deep sand beds, which were trying to replicate the same effect. The Marine hobby elected to stick with shallow substrate layers, and dose carbon sources to feed aerobic heterotrophs. They uptake excess N & P, and are then pulled out by a protein skimmer. But, without a way to skim off the excess bacterial load, it’s far more likely to result in negative water quality. However, I do think you did a great job with this test. And you did a good job of highlighting the other benefits such a setup adds to an aquarium. By including it, I had a much more diverse system that dealt with swings as a non-issue. Running a similar sediment layer in my sump tank as part of it's 'filtration' along side floating plants in the sump and abundant plants in the display served to create a near bullet proof system in terms of nutrient loads. Then you add in things like invertebrates and utilitarian fish which add nutrient cycling, and it creates a very stable aquarium system overall. Such a system had redundancy upon redundancy in terms of ecological services and ecological niche's. That created a tank which had to be dosed and fed heavy to maintain growth, but was very difficult to overfeed. But the goal of denitrification alone is a bit of a red herring.
Thanks for this experiment. I did want this to work but I have tried the same setup for a planted tank and there was no reduction in nitrates. I think what most folks who experience little or no nitrates in their tanks have assimilatory denitrification taking place (aside from plants). This is bacteria up-taking the nitrogen to grow. However, in this case the nitrogen continues to stay in the tank and never off-gases.
I have a 75 gallon with 5 large silver dollars and 2 large parrot fish and 2 large clown loaches. It doesn't have any plants in the tank because the silver dollars decimate any plant I put in. My nitrates were alway between 50-60ppm with weekly 50% water changes. I am using slow moving plenum and bcb basket in canister filter. It took 8 months before I saw nitrate reduction. Now after the 9th month my nitrates test at 5ppm. And I am now just doing 25% weekly water changes. My feeding amount has stayed constant. So I think it has been a success for me.
I can only imagine that duplicating the process, that occurs in nature, would be difficult considering the scale that nature has at it's disposal. Take lake Michigan, or the Atlantic Ocean, for example, compared to a 55-gallon glass box.
Your results mirror my own closely. I ran a similar test in a 33 xtra long over the course of 10 months in 1999. I am currently in the middle (6 months in) of testing Bio Home media. According to the manufacturer it is supposed to allow a "complete cycle" which would also eliminate nitrates. Frankly...It's not looking much better than the Anoxic system at this point. I would love to see you take a swing at it when time permits.
I have not conducted any experiments........ instinct tells me that I have anoxic filtration happening in my deep substrate and anaerobic filtration going on in the water colum. Honestly though I don't know how I would go about proving it . Your experiment has been a great tool for perspective. I vote for a school of pearl gormami with heavy plants.
That's true, but you wanted to see if you could definitely confirm that denitrification was taking place in an aquarium without plants being present . If you decide to continue your experiment and you find that denitrification does take place at a rate to eliminate the need for water changes to keep nitrate levels in check, then the argument could be made that running an undergravel filter in a fish only aquarium will eventually minimize the need for water changes as the filter bed becomes clogged with detritus. Remember, you're doing your testing without fish in the aquarium so the detritus buildup in your experiment is minimal and the undergravel filter has undergone minimal clogging since the initial set up.
Under 40ppm nitrates is a non-realistic goal without a significant purpose. Government tests show denitrification in the soil absent plants, but I can believe that a deep substrate (or anoxic system, which is different) is insufficient to greatly reduce nitrates by itself (that's where algae comes in when there is insufficient plant growth). However, while having plants gets in the way of testing... they are desirable in many ways and I can't imagine having a tank without them, regardless of whether I have no substrate, little substrate, or deep substrate. Thanks for sharing your results. I think your results are fine. You were testing anoxic conditions. Deep substrate setup without an undergravel filter would be interesting, but you've already spent 5 months on this setup. Thanks again.
That's true, but you wanted to see if you could definitely confirm that denitrification was taking place in an aquarium without plants being present . If you decide to continue your experiment and you find that denitrification does take place at a rate to eliminate the need for water changes to keep nitrate levels in check, then the argument could be made that running an undergravel filter in a fish only aquarium will eventually minimize the need for water changes as the filter bed becomes clogged with detritus. Remember, you're doing your testing without fish in the aquarium so the detritus buildup in your experiment is minimal and the undergravel filter has undergone minimal clogging since the initial set up. That's what I thought when I watched some of Dr. Novak's videos, but in other videos, he stated in smaller systems especially, it wasn't the functioning undergravel filter that was critical to creating anoxic conditions but the existence of the plenum. If you stop and think about it, then aesthetics aside (the detritus sitting on the gravel bed surface) this would allow for the creation of anoxic conditions as the oxygen in the plenum would be consumed it may not drop to anaerobic conditions due to diffusion of the nitrogen gas generated as a result of denitrification and the small amount of oxygen that is drawn into the plenum. This is speculation on my part, and not the result of experiments.
Thanks for the work. Would be interesting adding an established BCB and or carbon source.
2 дні тому
My question always is how anoxic is anoxic. In other words, if you have flow through the filter bed, you will have oxygen dissolved in the water flowing through. If the oxygen level has to be very low, you can't have flow. Now, if those bacteria function in a slightly lower oxygen concentration this can work. It just seems to much trouble. Most people aren't going to need it. In even a heavier stocked tank, It doesn't take massive amounts of normal cycling bacteria to be reduce ammonia/nitrites, and even a few plants can help more.
I don't know anoxic filtration works for nitrate reduction, but I made a plenum in order to achieve a reasonable slow water movement between root plants, not to fast. In theory, this slow movement helps to maintain a healthy substrate. And yeah, I have plants, I don't have any proof about nitrate control, but plants and fish are healthy. Regards
Thanks for the experiment. However, from my experience & experimenting with the anoxic filtration, 5 months is still not enough time. Mine took about 8 months plus before nitrates started coming down and I now have consistently zero nitrates. Initially my nitrates had gone up to around 120ppm even with weekly 25% water changes and 5 good sized goldfish in a 40 gallon tank with no plants. I have a canister filter running with bcb bags and a DIY 5 gallon bucket sump also with bcb bags. After around 8 months is when I started seeing the nitrate levels start coming down until it finally reached zero and I now do only 25% water changes only once a month apart from top offs. I did not have a plenum at that time. After seeing the benefits of the anoxic system, I now recently installed a plenum in the same tank and still consistently have zero nitrates and without any plants. The canister and 5 gallon sump are still running on the tank. From looking at the size of your tank, I would increase the bubbler slightly to increase the flow through the plenum a little more and give it a few more months to fully mature before passing judgement yet. Please give it a little more time & don't give up just yet. I was doubting the system myself when my nitrates started going up but I stuck with it patiently and it eventually matured worked out fine. By the way I did not add laterite or any iron source to either my bcb bags or the plenum as it was not available locally where I live. I also could not get the kitty litter and so I used broken bits of baked red clay pots & clay bricks from a local clay factory to make the bcb bags. Thanks once again for sharing your results so far.
@superaquatics interesting, your experience is similar to mine. It took about 8 months for my nitrates to go down in a plantless tank. I have other tanks using anoxic filtration that have plants and less fish load that took far less time. I think the best way is to gradually add fish allowing the bio filter to gradually build up to handle the load.
Tanks usually take a year to be perfectly balanced. But my method seems to work great with just topping off. After a year I change water when needed. Usually every 6 months because my monster fish.
I have had a deep sand bed plenum set up for two years on a 6 1/2 foot tank with two canister filters containing Biohome* media, has some plants and light stocking. Nitrates still go up. Tap water for changes has 20ppm. Always reads between 30 and 40ppm. *suppose to remove nitrates.
Yeah biohome doesn't work. It's one of the worst media ever invented, with lots of space occupied by the stoney material that has pores that are too small for bacterial colonies to develop in. And any bacteria inside get pretty much 0 nutrients as the water all flows around the material instead of through it.
@waterbird-s5q I think the substrate you use makes a difference. You won't get as good experience with sand as with fine gravel. Sand compacts too much to allow good flow. You have to crank up the flow rate. My experience with Sand over a plenum and rainbow fish in a 75 gal was I could not get less than 20ppm nitrates and I did have some plants. When I switched to a fine gravel the nitrates went to down to less than 5 ppm.
I like that you did an experiment on this topic Im generally not opposed to the idea of anoxic filtration working, but im also kinda of the opinion that any bacterial growth will also consume nitrogen, this lowering the levels in water Eighter way, i dont have a strong opinion on that But I almost feel like you made the test more difficult than it needed to be If you run two different filters on a run in tank with plants or like a african chichlid tank without them, as long as plants are keept roughly the same size and feeding schedules dont change, you also have a constant baseline for all intents and purposes Then any differences in nitrogen buildup can more likely be linked to filtration Plus you dont have to keep an ugly empty tank for months that you dose in a pattern, that isnt really close to how the fish would excrete ammonia as well
I first tried this out about 6 months ago or so and I have switched all my aquariums (10) to this anoxic undergravel filter system and I find that my tanks are just healthier overall and always clear however I was definitely wondering if it was getting rid of all the nitrates in the end 🤔 I will continue to use this system However all my tanks have other ways of filtering like canister filters and hang on The backs I would still recommend this system as it doesn't take up extra room And I've also noticed that the few tanks I have plants in - the roots are very healthy ✅ Oh I did reach zero everything in my south American Cichlid 120g But with UGF + canister + hang on back + plants 🤷:)
I have heavily planted aquarium and with deep aqua soil and fine sand substrate for months. Most of time nitrates is almost non existentant and only when the nitrate is high when there a bacterial bloom.
Please don't end the experiment! From my understanding anoxic and anaerobic bacteria need 6-18 months to grow. I would be really curious to see where it is at a 12 month look versus a 5. Thanks for doing this experiment and your will to not fill that tank with fish is impressive.
I ran also a experiment but with those big filter media that is big like a brick. (From the guy that does the pimp my filter UA-cam videos). And added a iron source. The idea were that the water flow and oxygen level should be low in the center of the brick and promote no3 anoxic conditions. I had cichlids and very dense planted tank. All stable and aged. The setup had a automatic feeder (3x times a day) so the input rate of in the END of no3 were the same from the food. More or less constant fish load with some growth and constant plant load. Had a high tech planted tank with CO2 and automated plant nutrient dosage pump. (Need to use a fertilizer that did not contain no3 when that influence and I got a lot of that already) all that on WiFi timers including lightning. I followed up weekly on a Swedish fish forum and measured no3. Despite 66% big water changes WEEKLY were needed to keep the no3 at a safe level for the fishes. I also got a RO-water filter that I made 0 ppm no3 water and reminelarze it. When my tap water in Malmö has 25 ppm no3! 😢😢 The experiment learned me: 1. Anoxic did not help me or worked in my experiment. Wasted money on the "bricks". 2. The amount and in a smaller degree type of food (I used same type during the experiment) will have a big impact on no3 levels! 3. It is the protein content in food that result in no3 4. Plants do a far better job of removing no3 than any anoxic filtration will do. When it is heavy planted with high amount of plant mass! 6. Use fertilizer without no3 if you already in your setup have a lot of no3. (Yes with low fish mass and low feeding in a planted tank then you maybe need to add no3!) 7. By reducing the automatic feeder to 1 time per day AND still have heavy planted tank. Then the plants consumes no3 and I don't need to do water changes more or less. So "overfeeding" or how much foid is added, is a bigger "issue" or contribute more to elevated no3 than any anoxic filtration can remove (if they remove anything at all). Bottom line is it were a good learning experience overall but I don't got any positive results of those two bricks in my filter that should be able to handle more than my modest 180 liter tank according to advertisements on the web page. And anoxic were a failure in this experiment and setup.😢
Try adding seachem denitrate as the media + microlift special blend liquid for 3 weeks then stop and let me know. Using those, I am able to get 0 nitrates at 4ppm ammonia per day.
I switched to anoxic systems in my fish tanks from traditional Hang on back filters and media because I was sick and tried of having to do water changes every week. Specifically I use a plenum alongside a canister filter filled with kitty litter with some sponges. I wasn't sure how effective the then new anoxic setup would be. So in order to gauge the effectiveness of the anoxic system I would test the water every week and only change the water if ammonia, nitrite and nitrates were out of spec. I kept a spreadsheet to record the results. Before with the HOB setup I needed to change the water weekly as my ammonia would climb to uncomfortable levels , with nitrates also being high at 50ppm. I tested my anoxic 120 Litre tank yesterday after 20 days and the ammonia, nitrites and nitrates are still at zero, and my 65 litre tank is the same except nitrates are at 10ppm, after 20 days. Phosphates for both 0.25ppm. Since the goal was reduced water changes, I used oversized canisters for both. I'm never going back to HOB and traditional media, as the water changes are less frequent and the cost of media alone is far cheaper. Edit: Just want to add that a plenum alone (I was hoping it would be enough due to the lower running costs of just an air pump.) was not sufficient for the bio load in my tanks and I added a canister with kitty litter and some sponge later with great results. Some tuning of the water flow rate through the plenum is also required as too fast or slow stops its effectiveness.
If your ammonia would climb before, then you had a problem there. You tank had too much life or too much ammonia leeching soil or etc. You didn't have a large enough nitrifying bacteria which means there is something else that was the problem i.e not a big enough filter or water flow. I am dosing ammonia chloride 4ppm every day and have 0 ammonia and 0 nitrite within 12 hours.
@@the_DOS That's why I had to do weekly water changes. I mean that's the point of water changes, isn't it, we change water because the water is getting polluted with excess ammonia, nitrite or nitrates. Otherwise their would be no need for water changes for water without that stuff.
@@ozhomerozmechwarrior4681 No that's not the point of water changes at all. I don't know where you read that or heard about it but it's plain 100% wrong. Ammonia and Nitrite should always be 0... in 1 day, in 1 week, in 1 month, in 1 year old water without a water change. Water changes are mostly needed for remove excess TDS and Nitrate. High Nitrates can kill fish. I have 5 tanks, most of them have discus and 2 of my tanks are overstocked. I feed the overstocked tanks 5-6 times a day but I have to do water changes because the nitrate goes above 80ppm. It tooks 2 months for the bacteria to be able to handle the amount of ammonia and nitrite load where I can measure 0ppm in ammonia and nitrite. Of course I didn't put all of them in the tank all at once. I have 0 ammonia and nitrite in all of my tanks. I have had 0 water change tanks before but the problem with them is that if you do a complete water change of 50%+ plus, many fish die. Reason being, is because there is huge difference between the new water and the water that was there for over months in TDS, etc.
@@the_DOS Of course ammonia and nitrites should be zero, but if their not because you got an ammonia spike for some reason (dead fish at the back of the tank in a hidden spot, power outage during a weekend away), what do you do, while your making adjustments to filtering or stocking levels? You do water changes until you get that stuff under control. amirite? Same thing goes with Nitrates. So your 100% comment is wrong. The point I was trying to make and perhaps did not express well was that you water change due to poor water quality. And the longer you can keep the water quality high, the less frequently you have to do water changes. My Anoxic setup has helped me do just that. Instead of changing water weekly, now I change water any where from 20 days to a month now. So I accomplished the goal of reducing the amount of water changes needed and the amount of work I need to do, as I want fish keeping to be a hobby not a job.
Personally, I think it's the zeolite (or maybe the way it is processed?) that impacts nitrate levels most. Most my tanks have a few bags of baked zeolite that have been allowed to absorb some seachem liquid iron, a layer of flourite, capped with sand (total substrate depth ranges from 20%-30% of total tank height, so probably considered 'deep') & all read 0/the lowest testable value on the test nitrates. A few have a bag of the baked zeolite under planted soil substrate, they also read no nitrates. I did a single tank with plant soil only & got nitrate readings the whole time it was set up. I recently set up a tub without any zeolite & it had high/40 nitrates after 2 weeks... I added a filter bag of baked zeolite to the tub next to the sponge filter & after 10 days the nitrates were untestable/ '0' & the TDS had fallen by 30%... I'm not sure if there is a limit to the zeolites capacity to essentially suck up nitrates & I don't know for sure if it is processing the nitrates per anoxic filtration standards, but I have a couple of tanks that are now more than a few years old & they still read '0' nitrates & TDS below 80 with minimal water changes (ie. 5%-10% weekly max as the species in them are sensitive to swings). My biggest interest is seeing if in the next few years this changes/a holding limit is reached or if it is indeed processing the nitrates as I suspect. In my case, I know it is not the plants processing nitrates in my tanks, as last summer I had a situation with one of my slow flow plenum tanks, where I had to remove over 99% of the plants (there were 3 plants left in the tank- a single light starved crypt, a single tiny echinodorus grisebachii 'tropica' & a single small light starved aponogeton). I made a stupid mistake that resulted in introducing a disease then mass death of the species in the tank... API test kit never registered anything. Sera liquid test kit was the same, nor did the test strips I got. They all showed 0/lowest testable values across the board (I've not shelled out for the expensive, highly accurate test kits that would show low level values as they are hundreds of dollars per single test or almost $1000 for a 3 pack 'value bundle' here, so just not worth the expense). The day after I removed the plants, I got a very slight nitrate reading (well under 5ppm) on the test strips, but none at all on the liquids. The only thing that decidedly increased was TDS- it shot up from 42 to 213 (that was my 'oh shite' moment & clued me into the fact there was probably decomposing bodies in there). Once I got all the bodies out & did daily small water changes for about 10 days, the TDS had dropped to 47/48 & there it has stayed. Some indian fern went back in after a few weeks & it has slowly taken over again during the last 8months, yet the tests still all read the same values as they did after 10 days of 10% water changes with once weekly 10% water changes. I do agree that generally speaking, most 'anoxic setups' aren't going to work the way most people want them to work.... I think the canister/sump BCBs probably help in smaller tanks... maybe?
@@BentleyPascoe What are you doubtful on? The zeolite or BCBs? If the zeolite, what would you suggest is reducing the nitrates when it is the only (known) variable? Doubt it's just a plain old mesh filter bag... TBF, I mostly keep nano or small species, so even my 'highly stocked' tanks are probably very low comparable to what most people keep. If BCBs, I'll have to defer to your opinion if you have played around with them, as I can't comment on how effective (or not) they are since I've never played around with them personally. My opinion is based solely on YT videos & then it's mixed & I've never seen people posting about them getting nitrates down to 0 TBH. Was more thinking a large BCB for a smaller tank might be enough to provide the higher percentage of filter to water/stock ratio... The issue being who wants a massive filter or sump on a small tank lol. The thing I found interesting, is even when the BCBs & anoxic filtration "work," it seems the people who had posted videos about them, usually move away from them after a few years, which I think is telling (providing they weren't just doing it for 'hot topic' content).
@@nixequestrian3721 zeolite doesn't take out nitrates specifically. It takes out ammonia faster than your filter bacteria. So what you were noticing is the zeolites are taking in the ammonia, which in turn stops ammonia from turning into nitrite, which then stops it from converting to nitrates. So yes, your nitrates went down because your zeolite is stopping ammonia from going through the cycle. This lasts until the zeolites are full of ammonia and can no longer store ammonia. Zeolite has 0 specific capabilties to store nitrates. However, newer resin like API nitra-zorb CAN store nitrates but these are not zeolite.
@@the_DOS That isn't correct. I've used it for new setups & get ammonia readings, then nitrite, then nitrate readings as per usual. Once the tank is established nitrates disappear. They don't if I don't use it in the setup. I've yet to run across an ammonia spike & some of the setups are now 5+ years old. So either the holding capacity is near limitless, or we are talking about 2 different zeolites. The stuff I use is labelled as 100% baked zeolite clay.
@@nixequestrian3721 You can check out the specifics of Zeolite in the scientific lititure and it will tell you the same thing I am telling you. It doesn't not do anything to Nitrates in the sense of it "capturing nitrates" but it does trap ammonia which in turn never gets the chance to convert to nitrite and then nitrates. Go put a few tablespoons of salt in the water and then watch all the ammonia leech out from the zeolite. You'll have a huge spike. That's how zeolite get's recharged. That's why many people do not use zeolite long term but only for short term ammonia spikes. You might not have any nitrates because of the low fish load per gallon of your tank or the balanced state of your tank w/ plants eating the nitrate load, or you might have an anoxic setup that you don't even know about in your substrate or filter. In one of my tanks, I have some aqua soil and some eco complete and after a few months, the soil was removing about 20ppm of nitrates per day with 0 plants. So i know even substrate can go anoxic.
This is truly fascinating. Every other attempt at this I've seen is a failry heavily planted tank. At that point it's impossible to say with any certainty of what is actually happening with the nitrogen cycle, isn't the nitrogen in ammonia more readily available to plants than in nitrate?
I mean it was too good to be true 😂 I was skeptical about such system full of nice claims of denitrification and all that stuff it can’t work like that
Your, as well as Novaks limiting factor, is a carbon source. I use vodka, about 2 ml daily. Minimal plants, so there is no way they are using up nitrates that well. Ive had to start overfeeding to get some nitrates. Interestingly, i have the same cloudy water as you. Then again, i have shrimp digging around, as well as a flow pump in the tank. I assumed it was those. Now, im not so sure.
If you turn off the air to the undergravel filter (leaving the sponge filter in operation to keep the oxygen level in the water column above the gravel surface constant), then once the oxygen in the gravel bed and under the filter plate has been consumed, then it should eventually stabilize at a much lower but not anaerobic level. If you find that the nitrate levels starting to drop over time, then you might start dosing with ammonia to determine if denitrification is now taking place at a rate sufficient to eliminate the need for water changes.
Yep mine is set upfor 2.5 years with 90% epiphyte plants and a 1 inch plenum all of the bottom of the tank with kiity litter and iron powder. Then organic potting soil then coarse gravel sand mix. Had algae for about 9 months then nothing after. Have manzanita wood and a 5 gallon sump fo a 40 gallon tank. Running CO2 the whole time. Dose full dose liquid fert after 2 week water changes and 40 fish. Nitrates sometimes gone sometimes Nitrates at 10 parts. I run 1 bubble a second with a 3/8 inch lift tube. I have a 90 gallon and a 65 also running the same way lots of fish and food. I do 50% water changes every other week and lots of fish. I really think that Bently would have better results with a better plenum and running the plenum slower for a longer period of time. So i could be wrong but i think this test is inconclusive . I believe his results and testing are interesting and appreciate.
Substantial anoxic denitrification in a home aquarium doesn't exist. There will either be too much flow, with too much oxygen, or too little flow, with too little nitrogen for bacteria to process.
@@the_DOS Could be assimilatory denitrification (using a source of carbon to fix nitrogen) or plants taking up the nitrogen. To get anoxic denitrification going at a measurable scale would require a number of conditions that simply cannot be met in an aquarium.
@@Aqua_Gino I have no plants. This is a dark cycled tank actually running right now. I had over 160ppm+ nitrates but I decided to change the media. I used 1 basket of expanded clay balls and 1 basket of seachem de-nitrate media. The reason i have expanded clay balls is because i wanted to see if I can create an anoxic condition inside of each ball. The results were after around 2 weeks with 0 water changes, I went from well over 160ppm to 0-10ppm depending on the time of day. I am dosing 4ppm ammonia chloride daily.
@@the_DOS Alright, well, it could technically only be assimilatory denitrification, which is not true denitrification as no gaseous nitrogen is formed in the presence of oxygen. (And there might be some capture of ammonia if there is zeolite or something similar present.) Problem is: how are you going to separate the NO3 from the O2? Because both will be present in the water you are trying to filter. It's not like there will be this selective influx of NO3 to the (supposedly) bio-active inside of porous media... Either both NO3 and O2 will be present or they won't. And in any case, bacteria need much more nutrients than the nearly non-existing water flow to the inside of media can support.
@@Aqua_Gino It could be, I am not sure what exactly it is in regards to the science. I am also not sure what is causing the condition... is it the expanded clay balls? Is it the denitrate media (which is basically matrix)? Maybe it's both? I will, after this tank is moved, do some testing on a 5 gallon bucket with a filter and different media. I will probably either make a post on reddit or a video about it on my channel. To me it's just incredible having almost 0 nitrates with heavy leeching Landen aquasoil + 4ppm ammonia chloride daily + 0 water changes + 0 plants.
Bentley... I've been watching your content for years... always interesting stuff. But after hearing what you said... your test results and observations, I'm boggled at your conclusion. I'm also disappointed that you went the ammonium chloride route instead of just feeding a silk stocking with appropriate food for X density of fish for the deemed time duration... because I cant (and most of us cant) visualize if X mg's of ammonium chloride is equivalent to fish food for 2 Oscars or 24 Oscars. so basically, Ammonia and nitrites stayed at zero for 6 months with 1 water change (for particulate)... without plants, which nobody says should not be incorporated into the system (Dr Novak actually suggested that It's quite good for plants _ the system)... How are these not fabulous results as compared to people having multiple filters and still doing weekly water changes? Also, with a couple plants incorporated to handle nitrate build up isnt it (superlative)?
@@spyrit35 Novak proposes that the anoxic bacteria consumes nitrates, naturally de nitrifying the water. The experiment is to show data. Can the anoxic conditions set up in a way Novak proposes to work, with just the system alone and without plants as plants consume nitrate and thus, make it inconclusive of the system actually works as proposed.
@@BentleyPascoe Okay Brother, I hear you. But the conclusion I got was that it's a heckuva filtration system all on it's own but you should add a few plants to deal with nitrate build up over time. Thanks for the data man.
I ran a similar setup in a 40 breeder for 2.5 years and never saw any significant results. I used a fine lava rock around and under the UGF, then a layer of kitty litter and Florite red. Capped it with fine gravel coarse sand mix, and lots of plants. My nitrates were always the same as my other tanks. Thanks for sharing.
were you doing regular water changes with the systems that you're comparing it to? think the water changes are what fatigue alot of us in the hobby.
@@spyrit35 I did weekly water changes
@@UncleSmileys.Aquariums Thanks so much for the answer, I've started and abandoned the hobby so many times because I love the hobby, but it's always the weekly water changes that make me hit the wall. Sometimes I have a really busy time and the weekend work just kills me... I dont remember frequent water changes as a child (Under gravel filter days) and I think I could sustain it again if Anoxic could space out that need.
I don’t do water changes on 4 of my big tanks and I don’t have 3 inches of sand on them. I think it’s all about balance. Plants filters and etc. I have very aggressive cichlids and iridescent sharks. I noticed that high nitrates equals low kh.
Wastewater treatment process analyst here. I appreciate you running this test so methodically and documenting every step of the way. However, I think one important limitation to your experiment is that facultative heterotrophic bacteria require a carbon source to denitrify in anoxic conditions. Most wastewater treatment plants use something in the way of methanol, but in an aquarium, the organic matter from fish waste, food, plant material, etc. would serve as your carbon source. That carbon is your limiting factor here, and without it, denitrification cannot take place.
You could consider dosing sugar as a carbon source and see what your nitrates look like in a few more weeks. I would hate to see those five months go to waste without that carbon.
Christian, you beat me to it. In the UK, around 1983, we had a denitrification system on sale which required a dose of methanol every week. It was a bit fiddly to maintain, but it worked. It never caught on, though.
Interesting. This has got to be the number one comment here. Thanks for mentioning this. Those of us who use the anoxic method have fish and fish food in the tank. There are a lot of factors going on. To assume that the anoxic doesn't work and it is just the plants is to make the same mistake as to assume that the plants don't work and the anoxic filter is the only factor.
So all he has proven if anything is adding pure ammonia to a fishless tank for a few months doesn't make denitrification occur in his particular setup.
Nailed it.
Thanks for the experiments. The results are always fascinating. Love your channel.
I was happy to see you roll with this test. I use anoxic setups for my four freshwater tanks and they run so so well. But as you've pointed out, I am one of those who has planted aquariums so no way my use of anoxic setups will test true denitrification. I still believe in the system and they are excellent for planted aquarium hobbyists. But I can't say first hand I've ever used anoxic as a solo method. No arguments from me my friend.
Now, plant that tank and drop in some cool fish that aren't rainbows hahaha. Enjoy
Why not rainbows?
@@fownine4life853 that's what the hahaha was for. Bentley loves rainbows and I'm sure he'll have at least one variety in there.
Just stop doing this shit bro it’s proved to be crap
Thanks for sharing and taking the time to experiment!
I have a 30g planted tank and use an anoxic filtration setup with an undergravel filter. Above it I have a mix of SafeTsorb and Brightwell Aquatics FlorinBase Laterin Subtrat VF in mesh bags sandwiched between layers of Eco Complete. I use a cannister filter to polish the water on top of that. I only run the undergravel filter at night. Personally, I never worried or even thought about the "denitrification" part of such a setup because, to your point, the plants take care of that. For me the benefit is the algae reduction and a way of using steady liquid fertilizer dosing to constantly recharge my substrate without having to use (or eventually replace) an active aquasoil. Being that I have 29 different plant species in the tank and they are growing out of control, I think, for my purposes, it's been a success.
Seeing your results, though, should give pause to anyone considering this setup as a way of reducing water changes in high bio-load / low plant tanks. I think you might be onto something by questioning an anoxic filtration system's ability of achieving natural denitrification in smaller water volume setups compared to the larger pond/lake level environments.
Brilliant idea for a video, Bentley! If I'm honest, I was expecting the results you got. It would have been fascinating to find the nitrates had dropped significantly. Realistically, though, I would assume that it would have to be a far deeper substrate with far more organic build up down there.
Interesting results. I am just happy that the tank is being planted.
Well, it came out similar to when I tried it a few years ago. I was enamored with this idea when I was a struggling college student and could barely afford my hobby, because it mimicked how substrate works in lake and river bottoms. So, I really wanted to replicate it at home and set up a similar process in my sump tank. Ultimately, I was never able to show it did anything. I had a few anecdotal wins. But looking at it critically: my tank was filtered by the abundant plant life in the display, and the duck weed I kept floating in the sump tank.
This process is well documented in nature and lab tests, we know it can work, and some industrial processes purposely mimic it. However, it's very difficult to establish it correctly in a home aquarium. And I remember posting similar criticism on Kevin's channel a few years ago.
It’s not a question of “does this process work?” It does, we know it does. Rather the question is “can we replicate this process in a small & closed system?” Something like a 50-100-gallon aquarium. And the most common answer seems to be “not really”. Or at least “not well”.
You could try carbon dosing it next, to see if you could accelerate and grow the bacterial population which would then have a higher respiration demand and thus hopefully denitrify. That's the next step. N probably isn't your limiting rate. Nor is P likely. Your limiting rate will either be a micronutrient (which is also unlikely) or simply C. What you probably ran into is your bacterial colony isn’t large enough to use up all the free oxygen in the sediment. So, it never needs the O from NO2 or NO3 in respiration. Which results in zero denitrification.
These target bacteria are facultative, meaning they can swap around being aerobic or anaerobic. Denitrification is a less efficient process, so they won’t do it if there is enough free oxygen in their surrounding environment (the sediment). You need the colony to be large enough to use up all the free oxygen first. And like most who attempt this, you don’t have the carrying capacity for the bacteria to hit that population size.
Regularly dosing a small amount of vinegar or vodka can jump start it and increase their population density. But, that's hard to regulate and is a moving target. When I tried it, I found it was very difficult to get a consistent result. And when you dose a carbon source to a tank, you’re more likely to grow heterotrophic aerobic bacteria instead.
That is the direction the marine side of the hobby went with carbon dosing. Instead of deep sand beds, which were trying to replicate the same effect. The Marine hobby elected to stick with shallow substrate layers, and dose carbon sources to feed aerobic heterotrophs. They uptake excess N & P, and are then pulled out by a protein skimmer. But, without a way to skim off the excess bacterial load, it’s far more likely to result in negative water quality.
However, I do think you did a great job with this test. And you did a good job of highlighting the other benefits such a setup adds to an aquarium. By including it, I had a much more diverse system that dealt with swings as a non-issue. Running a similar sediment layer in my sump tank as part of it's 'filtration' along side floating plants in the sump and abundant plants in the display served to create a near bullet proof system in terms of nutrient loads.
Then you add in things like invertebrates and utilitarian fish which add nutrient cycling, and it creates a very stable aquarium system overall. Such a system had redundancy upon redundancy in terms of ecological services and ecological niche's. That created a tank which had to be dosed and fed heavy to maintain growth, but was very difficult to overfeed.
But the goal of denitrification alone is a bit of a red herring.
I enjoy your experiments. Always eye opening
Great video, info and experiment.
Thanks for this experiment. I did want this to work but I have tried the same setup for a planted tank and there was no reduction in nitrates. I think what most folks who experience little or no nitrates in their tanks have assimilatory denitrification taking place (aside from plants). This is bacteria up-taking the nitrogen to grow. However, in this case the nitrogen continues to stay in the tank and never off-gases.
I have a 75 gallon with 5 large silver dollars and 2 large parrot fish and 2 large clown loaches. It doesn't have any plants in the tank because the silver dollars decimate any plant I put in. My nitrates were alway between 50-60ppm with weekly 50% water changes. I am using slow moving plenum and bcb basket in canister filter. It took 8 months before I saw nitrate reduction. Now after the 9th month my nitrates test at 5ppm. And I am now just doing 25% weekly water changes. My feeding amount has stayed constant. So I think it has been a success for me.
Oh, thanks good feedback!
That we probably needed to run the experiment longer than just 5 months..👍
I can only imagine that duplicating the process, that occurs in nature, would be difficult considering the scale that nature has at it's disposal. Take lake Michigan, or the Atlantic Ocean, for example, compared to a 55-gallon glass box.
Your results mirror my own closely. I ran a similar test in a 33 xtra long over the course of 10 months in 1999. I am currently in the middle (6 months in) of testing Bio Home media. According to the manufacturer it is supposed to allow a "complete cycle" which would also eliminate nitrates. Frankly...It's not looking much better than the Anoxic system at this point. I would love to see you take a swing at it when time permits.
@@rantsandreviews it's coming 😉
Thank you for sharing information
I have not conducted any experiments........ instinct tells me that I have anoxic filtration happening in my deep substrate and anaerobic filtration going on in the water colum. Honestly though I don't know how I would go about proving it . Your experiment has been a great tool for perspective. I vote for a school of pearl gormami with heavy plants.
That's true, but you wanted to see if you could definitely confirm that denitrification was taking place in an aquarium without plants being present . If you decide to continue your experiment and you find that denitrification does take place at a rate to eliminate the need for water changes to keep nitrate levels in check, then the argument could be made that running an undergravel filter in a fish only aquarium will eventually minimize the need for water changes as the filter bed becomes clogged with detritus. Remember, you're doing your testing without fish in the aquarium so the detritus buildup in your experiment is minimal and the undergravel filter has undergone minimal clogging since the initial set up.
You did it wrong and I'm furious about it!😆
I vote you get dwarf chain loaches!
@@John-Ebsen 🤣
Under 40ppm nitrates is a non-realistic goal without a significant purpose. Government tests show denitrification in the soil absent plants, but I can believe that a deep substrate (or anoxic system, which is different) is insufficient to greatly reduce nitrates by itself (that's where algae comes in when there is insufficient plant growth). However, while having plants gets in the way of testing... they are desirable in many ways and I can't imagine having a tank without them, regardless of whether I have no substrate, little substrate, or deep substrate. Thanks for sharing your results. I think your results are fine. You were testing anoxic conditions. Deep substrate setup without an undergravel filter would be interesting, but you've already spent 5 months on this setup. Thanks again.
That's true, but you wanted to see if you could definitely confirm that denitrification was taking place in an aquarium without plants being present . If you decide to continue your experiment and you find that denitrification does take place at a rate to eliminate the need for water changes to keep nitrate levels in check, then the argument could be made that running an undergravel filter in a fish only aquarium will eventually minimize the need for water changes as the filter bed becomes clogged with detritus. Remember, you're doing your testing without fish in the aquarium so the detritus buildup in your experiment is minimal and the undergravel filter has undergone minimal clogging since the initial set up.
That's what I thought when I watched some of Dr. Novak's videos, but in other videos, he stated in smaller systems especially, it wasn't the functioning undergravel filter that was critical to creating anoxic conditions but the existence of the plenum. If you stop and think about it, then aesthetics aside (the detritus sitting on the gravel bed surface) this would allow for the creation of anoxic conditions as the oxygen in the plenum would be consumed it may not drop to anaerobic conditions due to diffusion of the nitrogen gas generated as a result of denitrification and the small amount of oxygen that is drawn into the plenum. This is speculation on my part, and not the result of experiments.
Thanks for the work. Would be interesting adding an established BCB and or carbon source.
My question always is how anoxic is anoxic. In other words, if you have flow through the filter bed, you will have oxygen dissolved in the water flowing through. If the oxygen level has to be very low, you can't have flow. Now, if those bacteria function in a slightly lower oxygen concentration this can work.
It just seems to much trouble. Most people aren't going to need it. In even a heavier stocked tank, It doesn't take massive amounts of normal cycling bacteria to be reduce ammonia/nitrites, and even a few plants can help more.
I don't know anoxic filtration works for nitrate reduction, but I made a plenum in order to achieve a reasonable slow water movement between root plants, not to fast. In theory, this slow movement helps to maintain a healthy substrate.
And yeah, I have plants, I don't have any proof about nitrate control, but plants and fish are healthy.
Regards
Thanks for the experiment. However, from my experience & experimenting with the anoxic filtration, 5 months is still not enough time. Mine took about 8 months plus before nitrates started coming down and I now have consistently zero nitrates. Initially my nitrates had gone up to around 120ppm even with weekly 25% water changes and 5 good sized goldfish in a 40 gallon tank with no plants. I have a canister filter running with bcb bags and a DIY 5 gallon bucket sump also with bcb bags. After around 8 months is when I started seeing the nitrate levels start coming down until it finally reached zero and I now do only 25% water changes only once a month apart from top offs. I did not have a plenum at that time. After seeing the benefits of the anoxic system, I now recently installed a plenum in the same tank and still consistently have zero nitrates and without any plants. The canister and 5 gallon sump are still running on the tank.
From looking at the size of your tank, I would increase the bubbler slightly to increase the flow through the plenum a little more and give it a few more months to fully mature before passing judgement yet. Please give it a little more time & don't give up just yet. I was doubting the system myself when my nitrates started going up but I stuck with it patiently and it eventually matured worked out fine.
By the way I did not add laterite or any iron source to either my bcb bags or the plenum as it was not available locally where I live. I also could not get the kitty litter and so I used broken bits of baked red clay pots & clay bricks from a local clay factory to make the bcb bags.
Thanks once again for sharing your results so far.
@superaquatics interesting, your experience is similar to mine. It took about 8 months for my nitrates to go down in a plantless tank. I have other tanks using anoxic filtration that have plants and less fish load that took far less time. I think the best way is to gradually add fish allowing the bio filter to gradually build up to handle the load.
what is bcb? what media did you use?
@@the_DOSbcb is Biocenosis Baskets.
The media I used is broken gravel from baked red clay pots and bricks.
Tanks usually take a year to be perfectly balanced. But my method seems to work great with just topping off. After a year I change water when needed. Usually every 6 months because my monster fish.
I have had a deep sand bed plenum set up for two years on a 6 1/2 foot tank with two canister filters containing Biohome* media, has some plants and light stocking. Nitrates still go up. Tap water for changes has 20ppm. Always reads between 30 and 40ppm.
*suppose to remove nitrates.
Yeah biohome doesn't work. It's one of the worst media ever invented, with lots of space occupied by the stoney material that has pores that are too small for bacterial colonies to develop in. And any bacteria inside get pretty much 0 nutrients as the water all flows around the material instead of through it.
@waterbird-s5q I think the substrate you use makes a difference. You won't get as good experience with sand as with fine gravel. Sand compacts too much to allow good flow. You have to crank up the flow rate. My experience with Sand over a plenum and rainbow fish in a 75 gal was I could not get less than 20ppm nitrates and I did have some plants. When I switched to a fine gravel the nitrates went to down to less than 5 ppm.
@icarlsw34 yes, could be a factor. I do have a layer of gravel and soil mix for the plants but it is predominately sand.
@@waterbird-s5q Yes, I had sand over safetsorb.
I like that you did an experiment on this topic
Im generally not opposed to the idea of anoxic filtration working, but im also kinda of the opinion that any bacterial growth will also consume nitrogen, this lowering the levels in water
Eighter way, i dont have a strong opinion on that
But I almost feel like you made the test more difficult than it needed to be
If you run two different filters on a run in tank with plants or like a african chichlid tank without them, as long as plants are keept roughly the same size and feeding schedules dont change, you also have a constant baseline for all intents and purposes
Then any differences in nitrogen buildup can more likely be linked to filtration
Plus you dont have to keep an ugly empty tank for months that you dose in a pattern, that isnt really close to how the fish would excrete ammonia as well
I first tried this out about 6 months ago or so and I have switched all my aquariums (10) to this anoxic undergravel filter system and I find that my tanks are just healthier overall and always clear however I was definitely wondering if it was getting rid of all the nitrates in the end 🤔
I will continue to use this system
However all my tanks have other ways of filtering like canister filters and hang on The backs
I would still recommend this system as it doesn't take up extra room
And I've also noticed that the few tanks I have plants in - the roots are very healthy ✅
Oh I did reach zero everything in my south American Cichlid 120g
But with UGF + canister + hang on back + plants 🤷:)
I believe a carbon source is the limiting factor. Try dosing vodka or sugar in measured amounts and re-test.
I have heavily planted aquarium and with deep aqua soil and fine sand substrate for months. Most of time nitrates is almost non existentant and only when the nitrate is high when there a bacterial bloom.
Please don't end the experiment! From my understanding anoxic and anaerobic bacteria need 6-18 months to grow. I would be really curious to see where it is at a 12 month look versus a 5. Thanks for doing this experiment and your will to not fill that tank with fish is impressive.
I ran also a experiment but with those big filter media that is big like a brick. (From the guy that does the pimp my filter UA-cam videos). And added a iron source.
The idea were that the water flow and oxygen level should be low in the center of the brick and promote no3 anoxic conditions.
I had cichlids and very dense planted tank. All stable and aged.
The setup had a automatic feeder (3x times a day) so the input rate of in the END of no3 were the same from the food.
More or less constant fish load with some growth and constant plant load.
Had a high tech planted tank with CO2 and automated plant nutrient dosage pump. (Need to use a fertilizer that did not contain no3 when that influence and I got a lot of that already) all that on WiFi timers including lightning.
I followed up weekly on a Swedish fish forum and measured no3. Despite 66% big water changes WEEKLY were needed to keep the no3 at a safe level for the fishes.
I also got a RO-water filter that I made 0 ppm no3 water and reminelarze it.
When my tap water in Malmö has 25 ppm no3! 😢😢
The experiment learned me:
1. Anoxic did not help me or worked in my experiment. Wasted money on the "bricks".
2. The amount and in a smaller degree type of food (I used same type during the experiment) will have a big impact on no3 levels!
3. It is the protein content in food that result in no3
4. Plants do a far better job of removing no3 than any anoxic filtration will do. When it is heavy planted with high amount of plant mass!
6. Use fertilizer without no3 if you already in your setup have a lot of no3. (Yes with low fish mass and low feeding in a planted tank then you maybe need to add no3!)
7. By reducing the automatic feeder to 1 time per day AND still have heavy planted tank. Then the plants consumes no3 and I don't need to do water changes more or less. So "overfeeding" or how much foid is added, is a bigger "issue" or contribute more to elevated no3 than any anoxic filtration can remove (if they remove anything at all).
Bottom line is it were a good learning experience overall but I don't got any positive results of those two bricks in my filter that should be able to handle more than my modest 180 liter tank according to advertisements on the web page.
And anoxic were a failure in this experiment and setup.😢
Try adding seachem denitrate as the media + microlift special blend liquid for 3 weeks then stop and let me know. Using those, I am able to get 0 nitrates at 4ppm ammonia per day.
I switched to anoxic systems in my fish tanks from traditional Hang on back filters and media because I was sick and tried of having to do water changes every week.
Specifically I use a plenum alongside a canister filter filled with kitty litter with some sponges. I wasn't sure how effective the then new anoxic setup would be. So in order to gauge the effectiveness of the anoxic system I would test the water every week and only change the water if ammonia, nitrite and nitrates were out of spec. I kept a spreadsheet to record the results. Before with the HOB setup I needed to change the water weekly as my ammonia would climb to uncomfortable levels , with nitrates also being high at 50ppm. I tested my anoxic 120 Litre tank yesterday after 20 days and the ammonia, nitrites and nitrates are still at zero, and my 65 litre tank is the same except nitrates are at 10ppm, after 20 days. Phosphates for both 0.25ppm. Since the goal was reduced water changes, I used oversized canisters for both. I'm never going back to HOB and traditional media, as the water changes are less frequent and the cost of media alone is far cheaper. Edit: Just want to add that a plenum alone (I was hoping it would be enough due to the lower running costs of just an air pump.) was not sufficient for the bio load in my tanks and I added a canister with kitty litter and some sponge later with great results. Some tuning of the water flow rate through the plenum is also required as too fast or slow stops its effectiveness.
If your ammonia would climb before, then you had a problem there. You tank had too much life or too much ammonia leeching soil or etc. You didn't have a large enough nitrifying bacteria which means there is something else that was the problem i.e not a big enough filter or water flow.
I am dosing ammonia chloride 4ppm every day and have 0 ammonia and 0 nitrite within 12 hours.
@@the_DOS That's why I had to do weekly water changes. I mean that's the point of water changes, isn't it, we change water because the water is getting polluted with excess ammonia, nitrite or nitrates. Otherwise their would be no need for water changes for water without that stuff.
@@the_DOS I had 3 big HOB's packed with media.
@@ozhomerozmechwarrior4681 No that's not the point of water changes at all. I don't know where you read that or heard about it but it's plain 100% wrong. Ammonia and Nitrite should always be 0... in 1 day, in 1 week, in 1 month, in 1 year old water without a water change. Water changes are mostly needed for remove excess TDS and Nitrate. High Nitrates can kill fish. I have 5 tanks, most of them have discus and 2 of my tanks are overstocked. I feed the overstocked tanks 5-6 times a day but I have to do water changes because the nitrate goes above 80ppm. It tooks 2 months for the bacteria to be able to handle the amount of ammonia and nitrite load where I can measure 0ppm in ammonia and nitrite. Of course I didn't put all of them in the tank all at once. I have 0 ammonia and nitrite in all of my tanks. I have had 0 water change tanks before but the problem with them is that if you do a complete water change of 50%+ plus, many fish die. Reason being, is because there is huge difference between the new water and the water that was there for over months in TDS, etc.
@@the_DOS Of course ammonia and nitrites should be zero, but if their not because you got an ammonia spike for some reason (dead fish at the back of the tank in a hidden spot, power outage during a weekend away), what do you do, while your making adjustments to filtering or stocking levels? You do water changes until you get that stuff under control. amirite? Same thing goes with Nitrates. So your 100% comment is wrong. The point I was trying to make and perhaps did not express well was that you water change due to poor water quality. And the longer you can keep the water quality high, the less frequently you have to do water changes. My Anoxic setup has helped me do just that. Instead of changing water weekly, now I change water any where from 20 days to a month now. So I accomplished the goal of reducing the amount of water changes needed and the amount of work I need to do, as I want fish keeping to be a hobby not a job.
Personally, I think it's the zeolite (or maybe the way it is processed?) that impacts nitrate levels most. Most my tanks have a few bags of baked zeolite that have been allowed to absorb some seachem liquid iron, a layer of flourite, capped with sand (total substrate depth ranges from 20%-30% of total tank height, so probably considered 'deep') & all read 0/the lowest testable value on the test nitrates. A few have a bag of the baked zeolite under planted soil substrate, they also read no nitrates. I did a single tank with plant soil only & got nitrate readings the whole time it was set up.
I recently set up a tub without any zeolite & it had high/40 nitrates after 2 weeks... I added a filter bag of baked zeolite to the tub next to the sponge filter & after 10 days the nitrates were untestable/ '0' & the TDS had fallen by 30%...
I'm not sure if there is a limit to the zeolites capacity to essentially suck up nitrates & I don't know for sure if it is processing the nitrates per anoxic filtration standards, but I have a couple of tanks that are now more than a few years old & they still read '0' nitrates & TDS below 80 with minimal water changes (ie. 5%-10% weekly max as the species in them are sensitive to swings).
My biggest interest is seeing if in the next few years this changes/a holding limit is reached or if it is indeed processing the nitrates as I suspect.
In my case, I know it is not the plants processing nitrates in my tanks, as last summer I had a situation with one of my slow flow plenum tanks, where I had to remove over 99% of the plants (there were 3 plants left in the tank- a single light starved crypt, a single tiny echinodorus grisebachii 'tropica' & a single small light starved aponogeton). I made a stupid mistake that resulted in introducing a disease then mass death of the species in the tank...
API test kit never registered anything. Sera liquid test kit was the same, nor did the test strips I got. They all showed 0/lowest testable values across the board (I've not shelled out for the expensive, highly accurate test kits that would show low level values as they are hundreds of dollars per single test or almost $1000 for a 3 pack 'value bundle' here, so just not worth the expense).
The day after I removed the plants, I got a very slight nitrate reading (well under 5ppm) on the test strips, but none at all on the liquids.
The only thing that decidedly increased was TDS- it shot up from 42 to 213 (that was my 'oh shite' moment & clued me into the fact there was probably decomposing bodies in there). Once I got all the bodies out & did daily small water changes for about 10 days, the TDS had dropped to 47/48 & there it has stayed.
Some indian fern went back in after a few weeks & it has slowly taken over again during the last 8months, yet the tests still all read the same values as they did after 10 days of 10% water changes with once weekly 10% water changes.
I do agree that generally speaking, most 'anoxic setups' aren't going to work the way most people want them to work.... I think the canister/sump BCBs probably help in smaller tanks... maybe?
@@nixequestrian3721 pretty doubtful on that to be honest.
@@BentleyPascoe What are you doubtful on? The zeolite or BCBs?
If the zeolite, what would you suggest is reducing the nitrates when it is the only (known) variable? Doubt it's just a plain old mesh filter bag... TBF, I mostly keep nano or small species, so even my 'highly stocked' tanks are probably very low comparable to what most people keep.
If BCBs, I'll have to defer to your opinion if you have played around with them, as I can't comment on how effective (or not) they are since I've never played around with them personally. My opinion is based solely on YT videos & then it's mixed & I've never seen people posting about them getting nitrates down to 0 TBH.
Was more thinking a large BCB for a smaller tank might be enough to provide the higher percentage of filter to water/stock ratio... The issue being who wants a massive filter or sump on a small tank lol.
The thing I found interesting, is even when the BCBs & anoxic filtration "work," it seems the people who had posted videos about them, usually move away from them after a few years, which I think is telling (providing they weren't just doing it for 'hot topic' content).
@@nixequestrian3721 zeolite doesn't take out nitrates specifically. It takes out ammonia faster than your filter bacteria. So what you were noticing is the zeolites are taking in the ammonia, which in turn stops ammonia from turning into nitrite, which then stops it from converting to nitrates. So yes, your nitrates went down because your zeolite is stopping ammonia from going through the cycle. This lasts until the zeolites are full of ammonia and can no longer store ammonia. Zeolite has 0 specific capabilties to store nitrates. However, newer resin like API nitra-zorb CAN store nitrates but these are not zeolite.
@@the_DOS That isn't correct. I've used it for new setups & get ammonia readings, then nitrite, then nitrate readings as per usual. Once the tank is established nitrates disappear. They don't if I don't use it in the setup.
I've yet to run across an ammonia spike & some of the setups are now 5+ years old. So either the holding capacity is near limitless, or we are talking about 2 different zeolites. The stuff I use is labelled as 100% baked zeolite clay.
@@nixequestrian3721 You can check out the specifics of Zeolite in the scientific lititure and it will tell you the same thing I am telling you. It doesn't not do anything to Nitrates in the sense of it "capturing nitrates" but it does trap ammonia which in turn never gets the chance to convert to nitrite and then nitrates. Go put a few tablespoons of salt in the water and then watch all the ammonia leech out from the zeolite. You'll have a huge spike. That's how zeolite get's recharged. That's why many people do not use zeolite long term but only for short term ammonia spikes. You might not have any nitrates because of the low fish load per gallon of your tank or the balanced state of your tank w/ plants eating the nitrate load, or you might have an anoxic setup that you don't even know about in your substrate or filter. In one of my tanks, I have some aqua soil and some eco complete and after a few months, the soil was removing about 20ppm of nitrates per day with 0 plants. So i know even substrate can go anoxic.
You forgot the two main ingredients for anoxic filtration to work properly: a fake PhD and a good anecdote.
😂😂😂😂
@@Cancertrain I have my PhD in BS 😉
This is truly fascinating. Every other attempt at this I've seen is a failry heavily planted tank. At that point it's impossible to say with any certainty of what is actually happening with the nitrogen cycle, isn't the nitrogen in ammonia more readily available to plants than in nitrate?
@@matthewsmith22 yes, but they will consume both.
I mean it was too good to be true 😂
I was skeptical about such system full of nice claims of denitrification and all that stuff it can’t work like that
As you have just found out , it is the plants.
Your, as well as Novaks limiting factor, is a carbon source. I use vodka, about 2 ml daily. Minimal plants, so there is no way they are using up nitrates that well. Ive had to start overfeeding to get some nitrates.
Interestingly, i have the same cloudy water as you. Then again, i have shrimp digging around, as well as a flow pump in the tank. I assumed it was those. Now, im not so sure.
Same here . One year with nitrate. Use Dr. Novack design. Can handle large bioload with water changes. Same as all my other aquariums.🐟
If you turn off the air to the undergravel filter (leaving the sponge filter in operation to keep the oxygen level in the water column above the gravel surface constant), then once the oxygen in the gravel bed and under the filter plate has been consumed, then it should eventually stabilize at a much lower but not anaerobic level. If you find that the nitrate levels starting to drop over time, then you might start dosing with ammonia to determine if denitrification is now taking place at a rate sufficient to eliminate the need for water changes.
@@jerryleong7605 that isn't how Novak sets his plenums up. So it would invalidate the experiment.
Dr. Novak specifies that a minimal flow through the substrate via mechanical means must be maintained for the system to work properly.
Fancy, slow filters are out. High flow filter outlet into a basket of mint roots is in! (Careful the mint doesn't eat your pets and kids)
@@CatFish107 Feed me Seymour... 😉
It did not work because you forgot to align it with the True North!! 😂
5-6/months the bacteria will take to stabilize,hope you continue your test for year and half
@@Sunny-wp4fd not going to waste a year on the tank at this point, just being honest here.
Yep mine is set upfor 2.5 years with 90% epiphyte plants and a 1 inch plenum all of the bottom of the tank with kiity litter and iron powder. Then organic potting soil then coarse gravel sand mix. Had algae for about 9 months then nothing after. Have manzanita wood and a 5 gallon sump fo a 40 gallon tank. Running CO2 the whole time. Dose full dose liquid fert after 2 week water changes and 40 fish. Nitrates sometimes gone sometimes Nitrates at 10 parts. I run 1 bubble a second with a 3/8 inch lift tube. I have a 90 gallon and a 65 also running the same way lots of fish and food. I do 50% water changes every other week and lots of fish. I really think that Bently would have better results with a better plenum and running the plenum slower for a longer period of time. So i could be wrong but i think this test is inconclusive . I believe his results and testing are interesting and appreciate.
Pea puffer plz
Substantial anoxic denitrification in a home aquarium doesn't exist. There will either be too much flow, with too much oxygen, or too little flow, with too little nitrogen for bacteria to process.
I can guarantee it does. I have 0 nitrate in my setup with 4ppm ammonia added daily to my 3 month experiment of annoxic media.
@@the_DOS Could be assimilatory denitrification (using a source of carbon to fix nitrogen) or plants taking up the nitrogen. To get anoxic denitrification going at a measurable scale would require a number of conditions that simply cannot be met in an aquarium.
@@Aqua_Gino I have no plants. This is a dark cycled tank actually running right now. I had over 160ppm+ nitrates but I decided to change the media. I used 1 basket of expanded clay balls and 1 basket of seachem de-nitrate media. The reason i have expanded clay balls is because i wanted to see if I can create an anoxic condition inside of each ball. The results were after around 2 weeks with 0 water changes, I went from well over 160ppm to 0-10ppm depending on the time of day. I am dosing 4ppm ammonia chloride daily.
@@the_DOS Alright, well, it could technically only be assimilatory denitrification, which is not true denitrification as no gaseous nitrogen is formed in the presence of oxygen. (And there might be some capture of ammonia if there is zeolite or something similar present.)
Problem is: how are you going to separate the NO3 from the O2? Because both will be present in the water you are trying to filter. It's not like there will be this selective influx of NO3 to the (supposedly) bio-active inside of porous media... Either both NO3 and O2 will be present or they won't. And in any case, bacteria need much more nutrients than the nearly non-existing water flow to the inside of media can support.
@@Aqua_Gino It could be, I am not sure what exactly it is in regards to the science. I am also not sure what is causing the condition... is it the expanded clay balls? Is it the denitrate media (which is basically matrix)? Maybe it's both? I will, after this tank is moved, do some testing on a 5 gallon bucket with a filter and different media. I will probably either make a post on reddit or a video about it on my channel. To me it's just incredible having almost 0 nitrates with heavy leeching Landen aquasoil + 4ppm ammonia chloride daily + 0 water changes + 0 plants.
Bentley... I've been watching your content for years... always interesting stuff. But after hearing what you said... your test results and observations, I'm boggled at your conclusion. I'm also disappointed that you went the ammonium chloride route instead of just feeding a silk stocking with appropriate food for X density of fish for the deemed time duration... because I cant (and most of us cant) visualize if X mg's of ammonium chloride is equivalent to fish food for 2 Oscars or 24 Oscars. so basically, Ammonia and nitrites stayed at zero for 6 months with 1 water change (for particulate)... without plants, which nobody says should not be incorporated into the system (Dr Novak actually suggested that It's quite good for plants _ the system)... How are these not fabulous results as compared to people having multiple filters and still doing weekly water changes? Also, with a couple plants incorporated to handle nitrate build up isnt it (superlative)?
@@spyrit35 Novak proposes that the anoxic bacteria consumes nitrates, naturally de nitrifying the water. The experiment is to show data. Can the anoxic conditions set up in a way Novak proposes to work, with just the system alone and without plants as plants consume nitrate and thus, make it inconclusive of the system actually works as proposed.
@@BentleyPascoe Okay Brother, I hear you. But the conclusion I got was that it's a heckuva filtration system all on it's own but you should add a few plants to deal with nitrate build up over time. Thanks for the data man.