Thought I'd share a temporary fix for aptasia taking over. Buy a "drill pump". It's a 5.00 device that fits into your electric drill like a drill bit (Home Depot has them).Attach hoses to each end. The next time you do a water change use the strong suction the drill provides to suck up the aptasia. I removed many using this method. I bought 5 tiny Bergias 2 months ago & have not seen them since. I'm going to try a Copper-banded butterfly next. I had so many aptasia in my 95 gal tank the fish had to be careful swimming ! So I sucked them up using the drill pump. Just be careful not to drop the drill in the tank or your drain bucket...you know, being electric and all !