I observed in my tank today that my male Dalmatian Molly is swimming funny. He sort of swims in a "twitching" matter and it seems at times its hard for him to swim. I am at stage of doing weekly water changes. I have the temperature at 81 and the other fish I have in the tank seem to be fine...

I went to the local fish store last night, signed up my kids on a fish club and they received two new Silver Tip Tetras for free. I currently have three Dalmatian Mollies, and Female Betta. I put them in last night and they seem to be getting along with the current fish. I understand that...