I had bad bubble algae when I first started. The emerald crab I got did as much as he could to AVOID the stuff. I have syphoned it out with pumps of and a tooth brush. Ultimatly I took every rock out of my tank and scrubed them in one bucket and dipping them in 2 seperate buckets of clean water to get all the spores off. I haven't seen any in 8 months+.