Mkay, so I kind of already know the problem. My betta can see his reflection on the back of his glass tank. So I've tried putting up a background to help with that, but it did nothing. I know that darker colors absorb more light, so I tried putting a lighter background but that didn't work either. And its becoming problematic because I can see that he's stressed from constantly seeing his reflection. The only thing I can think of is putting something on the inside of the tank instead so that the glass can't reflect anything at all. But I'm not sure what to put, any suggestions? Help is appreciated!