. . . "Below are a few photos of a simple sump designed from a 20 gallon fish tank, and a slightly more elaborate design from a 30 gallon fish tank. 20 gallon sump with refugium before, and during operation. http://www.fishforum.com/userpix/47_20sumpnew_1.jpg http://www.fishforum.com/userpix/47_20sump_1.jpg 30 gallon sump with refugium before, and during operation. http://www.fishforum.com/userpix/47_30s" .