About two weeks ago I purchased some Zoanthids from the lfs They have been doing great up until this weekend. Polyps seem to be loosing color along with some of them not opening up, also notice some brown alge growing on the base of them and is starting to reach the and cover closed polyps. About a week ago they got knocked down and fell face first into substrat could that have hurt them is there anything I can do they are placed at bottom of tank now on substrate. The tank is A 25 gallon I have an ehime 2213 canister filter on it along with A powerhead rated at 650gph, Lighting consits of four T5 ho two white two blue. Any suggestions would be great Thank in advanced. Also all water leveals in tact Ammonia 0 Nitrite 0 PH 8.2 The tank has been up and running for about two months now. Have green star polyps, bubble, maxima clam, along with colt coral they are doing fantastic.