I've got a ten gallon tank, and I had four tetras (two pink, two blue if that matters) and a scavenger. I inherited two more blue tetras in an emergency tank leak, so now I have seven fish (I'm good at math!). Is that too many fish for a tank of this size? I wouldn't mind ditching the two extra tetras when the replacement tank is ready, but I can't tell the new fish from the old. Maybe it doesn't matter to fish, but I really don't want to break my guys up. So, if there aren't too many here, I'll probably just keep the new ones. According to the manual, it's recommended you have no more than 1 inch of tropical fish per gallon. Assuming tetras fall under the "tropical" banner, I think I'm okay. I'm guessing these guys are about an inch long.