They grow pretty quick. I started with 2 and ended up with about 10 in under a month. I bought two peppermint to eat them and at first, they wouldn't touch them, then all of a sudden over the course of 2, maybe 3 days, they were all gone. I hear butterfly fish will also eat them. Aiptasia X kills them, and also encourages feeding. Totally reef safe stuff. I was also told by the LFS that if your aiptasia munchers aren't munching, they will once you try to kill them with Aiptasia X.