I have a piece of Plexiglas mirror I planned on using on the back of the aquarium. Does this mean I can't have a Betta in the tank? What about the other fish. I know when I had my aquarium years ago, I used on, but I can't remember if I had a Betta in the tank. First I had to literally remodel the house to fit the aquarium in and now I am finding this is a lot more complicated than it seemed to be 30 years ago! Thyra