bta=bubble tip anemone. no, they are easy to keep alive. probably one of the easiest anemones. Carpets get big and are fish eaters so you might want to watch out for those, especiall in a 90 gallon tank that you have listed might be to small. also, an LTA (Long tentacle anemone) should be fine also. BTAs tend to stay on the rocks. LTAs tend to stay on the sand.