Im trying to find a cover for my new fish tank. it is a 20 gallon... thanks i already have fish... there in another tank but they keep breeding so time to move some to a new tank lol

I don't have any thing in it. Just a simple little plastic tank with a guppy and some sort of pink fish? I know they can live without any air filters because i've owned many before and even these ones have lived a long time. But i just finished cleaning it and the tank and fish are covered with little bubbles and the pink fish is floating round like it's about to die? Any idea what i can do to fix this?

How to calculate the surface area of a cylindrical tank cover if that cover was a part of a hollow sphere, while: D= Tank diameter H= Hight of the cover t= Thickness of tank wall= Thickness of cover.

My brother drove my car before me and got into several different accidents. The gas tank cover is totally missing. I've tried Kragen's but no luck.