I have a 55 gal. tank with 15-20 fish. I have a silver dollar and a florida flagfish. They do the strangest thngs. Ive had them both for 4-5 months, and they rub against each other swim side by side and, you won't believe this, but once I did a water change, and my silver dollar got shocked, and starting swimming sideways and upsidedown, and that flagfish actually was pushing him upright trying to keep him alive, and he did live. My dad could not believe what he saw. So what exactly is going on between the two?