Eric, In my fowlr I have a forty gallon sump with filter sock, big skimmer and a fluval fx5 cannister. I do a 20% water change about every three weeks. I could probably do less water changes but I'm pretty heavily stocked. I only feed once daily but I feed heavy. I used to run gfo but I don't keep up with that anymore. My fish seem fine even my Emporer and I'm getting ready to add a three spot angel when he's ready to come out of Quarentine. Is that spelled right? My spellcheck isn't working. My Emporer was maybe 2 inches when I got him and now he is about 6 or 8 and almost through his change. The nice thing about a fowlr is you can get some beautiful fish that won't work in a reef.