Well I have guppys and plattys in my tank because i love the colours and patterns on them. Though i do know they breed like crazy and some day they are going to over take my take. I have a LFS they will buy them off me or swap them for more fish or plants etc... Also i will be putting the preg fish in a breeding box so the fry have more chance to survive. Whats my Question? Well at what size roughly could i put the fry into the tank with other fish ?