Ive had a mantis, luckily he went in a bio cube i was working on, so I just kept him there for about a year, before he outgrew it and I got rid of him. Last time I bought rock fomr a LFS I cam home to find a mini maxi, and I mean mini maxi, this thing was the size of a quarter and never got any bigger. Bought a decent size piece from Elite a couple weeks and the thing was full of bright green nudis, or at least I think their nudis, ive counted 5 in my tank so far and the aptasia has pretty much gone away, NOW THAT WAS A SCORE.