Why not. I don't see any reasonyou shouldn't except that it won't be 22" fish anymore but more like 33(22+7+4). That should be fine as long as your tank is established long and well. Although, I think you will gonna run out of space if you keep all the live barer in the tank. I see you have Guppies and Mollys. They are quick to rpoduce off springs. You probably already know that. Maybe, you need to find their frys new home. Otherwise,I see your tank will be overcroud in near future.
