I ordered my Berghia to help with an outburst of aiptasia in my nano 16gl. When the order arrived I was skeptical do to the size. After a few weeks, little improvement, then I noticed a change. One rock, clean, two rocks, clean. I finally saw a larger Berghia then smaller ones. Yes, I ordered 3 and now have several with an aiptasia free tank. Patience is my only advise to people ordering.