What is the smallest you should make your return section?

[derek_s]

I have been laying out my new sump, and just wondering what is the smallest you should make the return section? It is a 40 gal breeder for a 140 gal tank, and the return may end up being an external.

I'd like to maximize refugium space, so how small can the return section be? I am running an ato, so that shouldnt be too big of an issue, I'm just unsure how much water my return lines hold. Is there a good minimum to work with?

 

[budsreef]

Another consideration for going small is water changes. With a small return area you will have to turn off your return pump to do a water change. On a 140G, if you do a 10% water change you would need 14G above the intake of your return pump if you want to keep it running.

 

[glxtrix]

I'd make it as small as you want....if you have a float switch in there to auto top off. If you dont, then a larger area would be better. Once power is out the water that drains into the sump has nothing to do with the return area. It'll raise your sump, yes. But it shouldnt overflow it....unless of course your baffels were measured wrong and are too high.