Joining two above ground ponds to central filter

[Peckoltia]

Hi

I have two above ground ponds that I would like to join together to feed into a central filter.

Both ponds have a fitting/tap on one end of the pond (bottom 3" of side wall) for plumbing. The filter is pressurized, so I will be unable to gravity feed it (large scale aquaculture bead filter). So a pump will be needed to draw water from the pond(s) and through the filter - I will also be adding my heater in line with this pipe.

My thoughts are if i connect the pump to the two bottom fitting of the pipe, push the water through the filter and back into both ponds, their is the potential that one pond will receive more water than the other and create an imbalance (potential flood).

What is the best way to work this to prevent a flood and ensure that the water level of both ponds is even? I can potentially add more fitting to the bottom of the ponds (would prefer not to).

I have attached a very rudimentary sketch of the system for reference. Please note that the filter and both ponds are sitting flat on a concrete slab.

Thanks,

 

[Peckoltia]

Just a quick idea - would adding an extra fitting/tap inline with the originals and connecting the two ponds together like this with some open plumbing keep both ponds at the same level? essentially creating one body of water.

 

[BIG FISH BOB]

I would be concerned about 2 things. 1. I agree It is possible/ probable that the water flow won't be even from both ponds (pulling more from the closest pond to the pump. Also with debris, it is possible that you may pull more water from one pond and send more to the other. Can you have a pipe connecting the ponds at the high water line to insure one doesn't overflow? My bigger concern would be with water flow.....the more the better. Do you plan to move water in other ways?

 

[fishdance]

I have a 10,000L pool and an 18,000 L pool running off one pressurized filter. Just place the 2 pools in series. So filter outflow pushes water into one pool which overflows into the second pool which returns to the filter. Use a large diameter overflow between pools if you want to minimize the water level difference between pools but to be honest, the fish and filter won't care what levels the pools are.

 

[fishdance]

If you have your heart set on keeping the two pools separate, just look at how a central sump and filter works on multi aquarium systems. Or RAS system. You control flow with the incoming water valve, don't use a tap on the drain side.

So just need to add a collection sump to your diagram.

Some advice to provide however. ... I would not put your pump before your filter as it will churn the waste water like a blender and pulverize fish poo to a fine mist making it much harder for your filter. Place pump after filter.

 

[fishdance]

I don't know how to edit my first post about using the 2 pools together.
I'm not sure if you know how to drain your pools reliably and I skipped over assuming you would know. My apologies.

Use a stand pipe on your first pool drain to set that pool's water level. This can be an internal or external stand pipe. There are several different methods to eliminate blockage on standpipe drains.

The second pool is in series so it feeds the filter (much lIke a sump). No standpipe is required on second pool.

 

[Peckoltia]

Hi Fishdance

I have attached another drawing of the potential set up where I am at.

I had always planned on having a standpipe, as i would use it as a waste line when doing autowater changes and to regulate the height of the water between the two ponds. I guess it also acts as a fail safe to some extent that one of the ponds cannot overflow due to the standpipe, could run the ponds dry in the long run if they are not sufficiently connected.

A 50mm pipe will adjoin both ponds to ensure that water is evenly distributed among the two ponds.

Can you see any issues with this?

 

[fishdance]

If you will be joining both pools together, you should use one input tap and one drain. Just think of both pools as a single pool. The water quality will be the same and there is less complexity so less things that could go wrong.

The weakness of this is your single 50mm connection pipe as any blockage will cause the first pool to overflow and the second pool to drain dry by pump.
To mitigate this risk you can use a TEE piece on the 50mm pipe placed vertically. The top side of TEE being the emergency overflow if the bottom side of TEE clogs.
I am unsure what flow rates you want so the 50mm pipe may be inadequate. These are gravity feed not pump feed connections. Doubling a pipes diameter will quadruple the flow through if you want a rough guide. This conecting pipe does not need to be straight, it is often a U shape placed underground but you have indicated you have a flat concrete slab.

Also many fish will instinctively hide in pipe so mesh off the output side of connecting pipe as well as input. It is amazing how much flow reduction a single fish can make.

You could also set a low water electrical shutoff on the pump as a safeguard. it depends on your stocking rate, how often you will be away, how precious the stock are to you etc.

 

[fishdance]

If you did want to keep two taps and two drains .... just use a common sump (open top). Sorry for the crappy photo edit.
Make sure the sump volume is sufficient to handle sudden overflow from power outages and any sudden suction from pump/filter on start up

 

[Peckoltia]

Would my original design work though?

Looking at the one you have created - The overflows would need to be moved higher, in a power outage I wont have a sump that can handle 6,000l if both ponds were to drain. Also, the ponds would either need to be raised or the sump low lying as the ponds are 860mm tall, wouldn't allow for much of a sump.

I totally get your design - but requires yet another sump/pond and i am short on space.