i grew 5 reds in a 29 gallon in my my house last year, although i ended up with 4 i think you could keep them till the summer. keep them well fed, i like blood worms for the little guys. (when u say dime size u mean 1" and under, i hope.) and most of all use common sense, change water, keep it clean, keep em' feed past that their easy. oh by the way, they are the **** at keggers, sometimes i go small mouth fishing right before a big party get something to feed my fish and entertain my guests. but thats me, a lot of ppl on this site will dissagree with that.