I was at a lfs on oahu the other day looking for a few fish to get rid of aggression in my tanks. they had yellow labs and firemouths in the same tank. i put 5 firemouths in my 30g and 24 hours later my hyper aggresive peacock mellowed out. my question is about my 20gh. I only had 2 juvenile fronts in it (1 inch). I put 4 yellows and 3 firemouths in it and I am wondering how long I need to wait until I separate them. the fronts are happy to have someone else in the tank and have quit fighting with each other. but everyone keeps saying that the firemouths will get aggressive. so far everything is OK. should I just wait until i see aggression or should I get the firemouths out at a certain size. I dont want my fronts to get messed with. the firemouths and the yellows are both about 1 1/2 inches. So far no aggression.