About 3 months ago I got 2 male Dalmatian mollies from my local aquarium shop and one of them has not grow much, if at all. The other one, however, has about doubled in size. I have 5 other goldfish in a 30 gallon tank. Ph is around 7, temp. around 75F. I feed them tetra flakes and some pellets for the bigger fish, and the smaller one is able to try to eat some of the flakes, but ends up spitting most if not all of it back out. Recently, I've noticed the bigger molly will chase the smaller one relentlessly and almost looks like he's trying to eat his fins, as some of them are tattered at the edges. Please let me know if there is anything I can do for the poor guy! Thanks!