A lot is down to head pressure of the system and pipework length too. For example; the distance between the bottom of the inlet of my drum and water level is 200mm. I have a 4" drain that runs a length of 6m inc fittings. Now I shut off my drum and drain it fully, when I re-open the ball valve to the drain, the flow under gravity back into my drum is just over 400 LPM, or 24,000 LPH. Which in my instance is more than enough to clear the bottom drain without having to have a purge valve as the pipeline holds around 50 litres of water and the drum holds about 70litres of water so the entire contents of my BD pipework can be emptied into my drum in one single flush. I'm not saying this is the case for everyone but pipework planning makes a huge difference when in the build stage. Not saying purge valves aren't needed but not all lines need them if planned correctly 🙂
A drum is totally different mate this is in reference to an eazypod and nexus . Where the head pressure is minimal fron the top of the inlet to the water level .
@@skeggy it's exactly the same principal Daz, Drum, easypod or Nexus. On a gravity system where filters are installed at water height, the only thing that determines the head pressure within the filter is the height between water level and the point at which the water enters the filter. A head height of 200mm in a drum, such as mine, eazypod or whatever is 0.02bar, the type of filter is irrelevant. The rest of the variables that determines the flow is down to internal pipe diameter and the length of the pipe.
@@UpNorthKoiPond the head height in a pod is much less than 200mm I'll check it I would guess its probably more like 75mm so the head pressure is less than half that also the drum runs straight in a a 4 inch line not reducing to 3 and going vertical I'll have to check the total volume of a pod can't remember off the top if my head but I would guess its also less than a drum chamber .
@@skeggy I had an eazypod on the old pond and the head height is much more than that. From the point at which water enters the pod to resting water height it's easily 200+ mm. I'm not trying to be argumentative with you mate but I think you have misunderstood the concepts of how flow & velocity is affected with it's 3 variables, (Pressure, pipe ID & length of pipe). You get the same flow whether the pipe is coming along & up or along, up and across. The only thing that matters are it's 3 variables, everything else is irrelevant 🙂👍
@@UpNorthKoiPond well i was always of the understanding more pipe more bends = more friction so less flow.. so if it can run horizontally in without the need for an elbow to change direction to vertical there would be more unrestricted flow ? i am going to put a tape measure front the bottom of the outlet to the Bottom of the overflows which would be the maximum you can get in a pod and from memory it's a lot less then 200mm
Agree completely with the need of a purge valve. I fitted a purge valve on the bottom drain line as soon as it came out of the ground, to minimise any settlement.👍
Seen loads of videos about purging bottom drains, but didn't install one when I re-built the pond last year. Personally I don't see the need for it, as you're always flushing the BD line when you empty and re-fill your filters. Each to their own I guess. Hope you're well and that the conservatory is still standing. Have a good trip to Denmark if I don't speak to you before you go. Stay safe.
Conservatory is just about standing .. thays the whole point of this video to show it doesn't actually purge the line because the inlet is too high in the filter so the head pressure is reduced to purge it has to be Anslow to the floor as possible to give maximum head pressure
Good call, would fit one if I ever get a easy pod, worth it, I have a huge multibay at mo, and the vortex takes all the rubbish out of my 4inch line when I purge it to clean the filter and top up, but I do think it is worth putting one in on the easy pod.
Flow rate is 5500 lph gravity fed probably nearer 5000 once its gone up a couple of feet yo the shower oase aquamax pump so flow is pretty accurate on them . Not a vari pump it's a 2 Inch drain it would be pointless on a 4 inch no where near enough flow rate
A lot is down to head pressure of the system and pipework length too. For example; the distance between the bottom of the inlet of my drum and water level is 200mm. I have a 4" drain that runs a length of 6m inc fittings.
Now I shut off my drum and drain it fully, when I re-open the ball valve to the drain, the flow under gravity back into my drum is just over 400 LPM, or 24,000 LPH. Which in my instance is more than enough to clear the bottom drain without having to have a purge valve as the pipeline holds around 50 litres of water and the drum holds about 70litres of water so the entire contents of my BD pipework can be emptied into my drum in one single flush.
I'm not saying this is the case for everyone but pipework planning makes a huge difference when in the build stage. Not saying purge valves aren't needed but not all lines need them if planned correctly 🙂
A drum is totally different mate this is in reference to an eazypod and nexus . Where the head pressure is minimal fron the top of the inlet to the water level .
@@skeggy it's exactly the same principal Daz, Drum, easypod or Nexus. On a gravity system where filters are installed at water height, the only thing that determines the head pressure within the filter is the height between water level and the point at which the water enters the filter. A head height of 200mm in a drum, such as mine, eazypod or whatever is 0.02bar, the type of filter is irrelevant.
The rest of the variables that determines the flow is down to internal pipe diameter and the length of the pipe.
@@UpNorthKoiPond the head height in a pod is much less than 200mm I'll check it I would guess its probably more like 75mm so the head pressure is less than half that also the drum runs straight in a a 4 inch line not reducing to 3 and going vertical I'll have to check the total volume of a pod can't remember off the top if my head but I would guess its also less than a drum chamber .
@@skeggy I had an eazypod on the old pond and the head height is much more than that. From the point at which water enters the pod to resting water height it's easily 200+ mm.
I'm not trying to be argumentative with you mate but I think you have misunderstood the concepts of how flow & velocity is affected with it's 3 variables, (Pressure, pipe ID & length of pipe). You get the same flow whether the pipe is coming along & up or along, up and across. The only thing that matters are it's 3 variables, everything else is irrelevant 🙂👍
@@UpNorthKoiPond well i was always of the understanding more pipe more bends = more friction so less flow.. so if it can run horizontally in without the need for an elbow to change direction to vertical there would be more unrestricted flow ? i am going to put a tape measure front the bottom of the outlet to the Bottom of the overflows which would be the maximum you can get in a pod and from memory it's a lot less then 200mm
Nice one Daz 👍👍💯💯
Agree completely with the need of a purge valve. I fitted a purge valve on the bottom drain line as soon as it came out of the ground, to minimise any settlement.👍
Good stuff daz bud 😊👍🐟
👌👍👍gotta agree mate , although i havent gotone on my small pond this video is certainly an eye opener 😲😲👍👍👍👍
Seen loads of videos about purging bottom drains, but didn't install one when I re-built the pond last year.
Personally I don't see the need for it, as you're always flushing the BD line when you empty and re-fill your filters.
Each to their own I guess.
Hope you're well and that the conservatory is still standing.
Have a good trip to Denmark if I don't speak to you before you go.
Stay safe.
Conservatory is just about standing .. thays the whole point of this video to show it doesn't actually purge the line because the inlet is too high in the filter so the head pressure is reduced to purge it has to be Anslow to the floor as possible to give maximum head pressure
Good call, would fit one if I ever get a easy pod, worth it, I have a huge multibay at mo, and the vortex takes all the rubbish out of my 4inch line when I purge it to clean the filter and top up, but I do think it is worth putting one in on the easy pod.
Wow that is filth. Always wondered if purge lines were realy necessary
Even though I'm pulling around 14k lph through my filter I still purge the drain once a month 👍
Have you had much out of it Jamie? Cause yours is fairly short run
@@skeggy no not really mate I don't really get much settling in the BD line
👌
What is the flow rate? Is the bottom drain 2 inch? I'd be concerned if that much came out 3 times a week Daz.
Flow rate is 5500 lph gravity fed probably nearer 5000 once its gone up a couple of feet yo the shower oase aquamax pump so flow is pretty accurate on them . Not a vari pump it's a 2 Inch drain it would be pointless on a 4 inch no where near enough flow rate