I vote for the butterfly. Actually, I added a Threadfin butterfly to my tank because they are one of my favorite fishes. To my pleasant surprise all of the aptaisia dissappeared from my tank within 2 weeks. I've seen lots of suggestions about using Copperbands but I haven't seen any reports about Threadfins. This butterfly has been in my tank for 2 years now and I never saw an aptaisia again. I'll think I'll keep her.