How many fish can I keep?
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- Опубліковано 15 вер 2024
- How many fish can I keep.
Hi its Lee from the Japanese Water Gardens, in this video I am going to be answering a question that I get asked almost every day.
It's a simple question but it certainly does not have a straightforward answer.
BOY DO I WISH IT DID!
Keep watching and I am going to try and answer how many fish can I keep in my pond?
TRY TO ANSWER.
In the old days of fishkeeping before the days of pumps and filters there was a simple formula that was often quoted.
You can keep 1” of fish for every square foot of surface area.
The basis of this formula was oxygen exchange at the surface.
To apply the formula you just needed to measure the length and width of the pond in feet.
You then multiplied them together to calculate the surface area.
You then divided the result by 4 the average length of a Goldfish and you had your answer.
So a pond 6ft by 5ft with no filter or pump could accommodate 30inch of fish, about 7 goldfish.
Now here is where things start to become vague.
Add an air pump and you can increase the number of fish by a significant margin. But as the number of fish increases you will start to get a buildup of ammonia, a toxic waste product excreted by the fish.
If the ammonia becomes concentrated in the water it will be harmful and possibly lethal to the fish.
In a modern pond there will be a biological filter designed to breakdown the ammonia into nitrites and nitrates, progressively less harmful compounds.
The more efficient the filter is the more ammonia it can breakdown and the more fish you can keep.
To further complicate the situation Goldfish and Koi are not the same. A 12” long Koi will need significantly more oxygen than 4 4” long goldfish and produce a significant amount more ammonia. A 12” long Koi will have a mass equivalent of approximately 30 goldfish.
So this old formula is of little use. It is far too simplistic to be relevant on a modern Koi pond with a good filtration system.
More elaborate formula do exist.
But they are a complete waste of time! The answer you would get has no importance to the average pond keeper.
The question of how many fish I can keep in a pond is actually a pointless question.
You can keep a huge amount of fish, if you have a massive filter, powerful aeration system and are prepared to do lots of regular water changes, but is this a sensible thing to do?
What if you have an electrical power failure or your pump malfunctions. How long will the fish survive?
Overcrowding is potentially a stress factor, the more fish you have, the more rapidly a disease or parasite will spread through the pond. .
The question that we should be asking is “How many fish should I have in my pond?”
When pushed for an answer I usually recommend 10 18” per 1,000 gallons.
Now I know others will disagree with this. But I believe that this number gives a good display.
Have less fish, but better fish. By that I mean don’t stock up your pond with lots of average, unremarkable fish.
Instead be selective. Be careful what you buy. Choose quality over quantity.
How many fish do you keep in your ponds?
Thank you for taking the time to watch this video. If you like what you see be sure to subscribe to the channel and give the video a thumbs up.
Its bye for now from Lee at the Japanese Water Gardens.
Good night, I like to apply a simple rule to goldfish. 1200cm2 for fancy and 2400cm2 for elongated fin, this calculation applies with 1 liter of midea per adult fish and a 10 times per hour renewal going through the mideas...
Another beautiful video thanks Lee 👍
excellent explanation. thank you good sir
Excellent video Lee for one minute I was thinking you had a formula for it the age old question the one that cant be answered you put it over the best way I have seen for along time thanks for filming
Thanks for the feedback. Your videos are very well done by the way. I hope you keep making them.
Brill vid Lee. I really like ur presentation as u get to the point n they r fun to watch. I have a 5500 litre pond with two large pressurised filters n two diy sieves at the top of my biohome shower filter. I only have fish that i like n each looks very different to the other 6 koi 5 butterfly koi 1 oranda which is the boss! 1 albino grass carp 1 black moor n 1 albino weather loach. They all get along n the water is good quality after reducing fish numbers n increasing filtration. May add a k1 static bed as they grow in the coming years.
Thanks for the feedback. I try to keep my videos relevant. I try to impart as much information as possible.
one adult koi /1000 in a well filtered pond with pristine water
Good video again lee
Glad you liked it. More on the way soon.
I follow the formula that fish should weigh no more than 1/1000 of the water. For long-bodied goldfish the general weight formula is length x length x length x 1,7 / 100. So, for example, a 10 cm long comet goldfish will weigh 10x10x10x1.7/100=17 g. It should live in a tank of at least 17 litres. I keep mine in 35 litres.
A perfectly reasonable suggestion. Does a good job of approximating the weight. By this system you would have a 39cm koi per 1,000 ltrs? give or take.
@@leecalladine Seems so.
What’s the maximum size Koi that you should have in say a 1000 gallon pond.?
24in is a large koi in a 1000 gallon.
I personally see it like this.
1000 gallons per koi then add on 5000 gallons after that.
That would be perfect for the Koi. Plenty of space for each fish. But most people would stock much heavier.
@@leecalladine yeah true. Also I'm just talking about the ideal most people cannot meet that.
Hello lee if you had 4,000 litres would this mean you can keep 8 koi or less..
Yes. But it's very much a case of it depends.
I have 1600gallons to 20 fish from 6inch to 18 inch so im going bigger now
Hi Lee, can You help, I live in a hostel in Manchester, We have just built a pond above ground level, I don't know the dimensions right now, it's approximately 4000 litres, We have goldfish, maybe 3", 3koi, 2 tench, all about the same size, in total I think 38 fish, can I obtain an ammonia tester?, as the filter system is run through a homemade wheelie bin, We have a 10,000 litre pump that flows over a waterfall but no extra areition, any input welcome, Thanks.
Ammonia test kits widely available through any aquatic retailer.
@@leecalladine Thanks Lee, sorry it's late, can I just ask, what time to slow feeding in the year?, they are still active and know food is coming, its gone in about 5 minutes, I don't want to pollute the water, they are having tetra pond sticks supplemented with prawns approx 8 hours later.
@@stewartgoodchild2930 Keep feeding the fish. Just reduced the amount. Consider switching to a wheatgerm based food. When the fish are not interested in the food stop feeding until the spring.
@@leecalladine Thanks Lee, will do.