I have a HUGH one in my 30cube. I did try and catch him, because I wanted to move him into my 150g aggressive. The only problem I have had with it is with my jaw fish. It goes in and bugs the jaw fish when I feed. Of course that doesn't go over well with the jaw fish at all. I have lots of small ones also, so would like to catch the big one and move it. But so far I haven't had any luck with the capture.