I had a great set up with my florida gar, clown knife, and retic ray. Well one of my friends had a 55 with a 12" florida gar so I took him in so he would have a larger tank. It went well for about two weeks before I looked and saw my awesome 10" gar that I have had since he was 2" missing an eye, bottom jaw ripped open, and with a torn up tail. Never shall I add more fish to a perfectly stable tank. Hopefully he will pull through.