All the fish are good at removal, its just you never know if they will deffinitly eradicate the issue. Also the fish will somtimes eat the aiptasia anf leave a piece of the foot behind for it to grow back. Berghias are crazy expensive, but they will only eat aiptasia and every last morsal they get there beeks on. The top priority is to get the berghias to breed, mine lay eggs every night but 80% of the time the eggs are eaten by amphipods. Ive always used berghias, and to be honest, the best thing to do is buy atleast 10 and hope for the best.