thanks for the advice. I have a 180 but I try to stay away from fish that get rather large like the naso tang, the 2 bar rabbitfish stays a bit smaller but still pretty big. I tried the algaefix marine a number of years ago when I didn't really know what I was doing so much and damaged a lot of my corals, I don't really like putting chemicals in the tank if I can avoid it. I think I'll check out aquahuts emerald crabs, I have good amount of bubble algae now, mine also started as a single or double bubble from a frag a number of months ago.