Hello everyone! My friend has a 20 gallon tall tank. It's been set up for a couple of years. When she gets rid of her platies, she would like to place an angelfish in the tank. I told her that this was not a good idea, and that an angel needs at least a 40 gallon tank (at least that's what I've heard). She doesn't want to listen to me, so I'd like a bit more information on angelfish. Aqadvisor tells me I can keep an angelfish in a 30 gallon aquarium. What is the minimum size for one angelfish? What is the minimum size for a pair? Does the pair need to be one female and one male or can it be two females so that she doesn't have to worry about them breeding? I know angels need a tall tank, but what kind of plants/rocks/wood do they prefer? Thanks!