Since my RD won't tolerate any tankmates and he is aggresive as hell has anyone ever put something in the tank for them to play with or beat up on ? I'm going to try and use a bobber by weighting it down with some sinkers and some fishing line. Has anyone ever tired this ? I just think it would be cool to see him beat up on something that he couldn't kill. I think I've read on another forum that some has used a super ball for their oscars.