i got some live rock that sprouted aiptasia so bad my friends made fun of me for having an aiptasia species tank. i added one lysmata wurdemanni for every ten gallons of tank, and within a week all aiptasia was gone, and i haven't seen any since. beware: lysmata californica are hard to distinguish from L. wurdemanni, and rhynchocinetes durbanensis & R. uritai are also sold as "peppermint shrimp". learn some latin, you will be amazed at what is passed off under "common names". people who say peppermint shrimp are not always apt to eat aiptasia probably bought the wrong kind. despite regular feeding, my L. wurdemanni seemed to go out of their way to eat my aiptasia.