[Myka]

Two Koralia 2's in not near enough flow. In my 33g I have a Koralia 2, and two MJ1200s. Even though the MJ1200 is rated as much lower flow it actually produces much more flow as the two are rated much differently with the Koralia using a propeller and the MJ using an impeller. Both the Koralia 2 and one of the MJ1200s run 24/7. The second MJ1200 is hidden behind the rocks, and I turn it on for 3-5 mins every morning. The purpose is to blow the detritus out from behind the rocks, but I can't leave it on all the time because it is too much flow for my LPS. I would suspect that you could add two Koralia 4's to your tank to take the place of the 2's, and then use one or both of your 2's behind the rocks. You could probably even leave the 2's on all the time.