I have an adult RES in a 29 gal. tank and have to do a 100% water change weekly. I use this filter
http://www.drsfostersmith.com/Produc...&N=2006+113827
in the tank and have it set up so it circulates the water in a circle around the tank. If the sponge gets clogged, you can simply pull it off and rinse it if you need to. I don't have mine set up to an ugf like the picture shows. I have it set up to suck the water in through the sponge, and out from where the tube is that is connected to the ugf in the picture. I have it running just like a normal powerhead would be set up in a tank with fish in it, except it's got the big sponge on the intake. His tank water still discolors, but all the solid waste and uneaten food is collected on the sponge.
