Hey, I'm actually new at this stuff of fishes. I got a male betta fish a few days ago, got him a 2.5-gallon tank it has a filter and heater. I never got any problems with him, for now hes a healthy happy fish. I decided to get a female fish, I brought her home, and put a divider in the fish tank. I know this may affect her so that why in planning to get a bigger one. Anyways the female is not interested in eating at all she barely eats and way to inactive. She has been like that for around three days and I'm starting to get worried.