Sump Flow question

[mmasuda31]

Hi all...I am new to the refugium

Here are the details...

I have a 40 gallon tank...overflow box in left corner.
Drain pipe is 1" and the intake flow into the refugium...protein skimmer in first chamber...macro algae and rocks etc in next chamber...and may pet a calcium reactor in last chamber...anyhow....I have the water going back up into the tank through a pipe that comes up through the overflow box...my question does it matter what flow I purchase for return?

I know water pumps are rated...but should I be getting a specific amount of water to throw back into the tank ?

 

[5pacey]

Yes ideally the same amount as what comes down the drain

The general rule of thumb is that there should be 3-5 X the volume of the DT water flow from DT -> sump -> DT.

This is different flow than what you need inside the DT. Inside the DT the rule of thumb is 10x the volume, but it depends on what type of animals you keep.

Spacey

 

[mmasuda31]

Awesome.

But, how in the world do I figure out how much water is coming through the overflow?

 

[5pacey]

Awesome.

But, how in the world do I figure out how much water is coming through the overflow?

One way would be to use RC's Drain/overflow calculator - http://www.reefcentral.com/index.php/drainoverflow-size-calc

Another, would be to use a 5 Gal bucket and a stop watch.

Yet another, and in the end what you want anyway, put a valve on the drain (gate valve, much more precise - which counts here), and then knowing the max it can handle in full syphon you can cut down on the flow to match the pump.

Conversely, you can put a T in the pump's return line back to the DT, which feeds back to the sump through a valve. This way you can adjust the amount of water the pump is pushing up to the tank.

Basically 1" drain can flow up to 600 GPH. You need a flow of 120 to 200 GPH through the sump for a 40 G tank. Get a pump which will do 300 Gph @ the head from your sump to the DT and you are set. You can then adjust the flow w/the gate valve on the drain line. If you put a T in the return line and get a more powerful pump you can use the extra flow to run reactors or a chiller.

Spacey

 

[BigKahuna]

Basically just get a pump a little more powerful than you need and valve it back to to suit your overflow.