Sump and Pump Question

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Aquarium Advice Regular
Feb 18, 2005
Potomac MD
Not a genius in fluid dynamics, so bear with me.

Simply: How do I determine equilibrium for my pump and overflow.

Have a 75G reef-ready with overflow. Sump is a 20G tank with a Mag 9.5 (950GPH) pump. Placed a flow valve between pump and return to govern the return.

My guess is that I restrict the flow from pump to tank, so that the overflow is just a bit quicker than the return... then once water drops below the overflow mark, it stops flowing to the tank, then the pump catches up.

Is this right?

Just trying to avoid disaster and divorce papers being filed for ruined floor and carpet... :)

As usual, thanks for the help.
That sounds about right. You should get the flow rating for your overflow lets say 700 gph, once you have that you should buy a pump that matches that flow rate at maximum head. Or like you said you can throttle down a stronger pump to match that of the overflow.

There is no game of catchup with the pump and the overflow. You will notice if your pump is too much for the overflow, generally the water level will be above the teeth on the overflow box and the water level inside the overflow box will be rather high. Throttle down your pump until the water level is just below the top of the teeth on the overflow box. If power goes out and the return pump goes out the water will continue to flow into your sump until in goes below the overflow box teeth. Make sure your sump has the capacity to handle the amount of water that keeps flowing when power goes out. Also remember water will back siphon from your return lines as well so you will need to either drill a hole in the return lines just below the water surface or you will need to get a check valve. I actually use both in my return lines just in case the checkvalve fails.

good luck.
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