WHAT , I have read somtimes can be stubborn but on enternet everwhere says good for begginers and for experinced but the only problem that Ive came across is that my fish seem to pick on it a little but dosent seem to bother it to much Im about to take the two of the three fish I have and try something new maybe more easy going or less aggressive towards my corals but, another thing is alge growth on it if you don't clean of alge could deterate(sorry can't spell)the outter layer or skin, but simple to clean ,soft new tooth brush seems to do the trick. IN all I think quit nice looking with or without polps showing . One other thing I really didn't like about the coral is that its nonsybolic( I think thats the word ) and only lives 1 to 2 yrs in captivity but I could be wrong I read to many books at once so sometimes I get two diffrent opinions. but its a nice coral and Ill keep u up to dated If you would like about any changes or deaths even though I have not killed anything yet(knock on wood).