Another option, if you keep up on water changes, is to go filter less. I had the rubble rock refugium in the middle chamber, and kept getting detrius and cyano all the time. Took all of that out, have a bag of purigen just hangning there, and filterfloss (polyfill) where chamber 1 flows into chamber two, and have been very happy with it. I feed heavy, but I also do a weekly 5 gallon water change.