I had a female betta in my 20gal high tank. She was a impulse buy and the only betta in the tank. These are pics of when she played "gerbil" . Being my hardiest fish she was the first to go back into the tank after it sat fishless for 2 months to get rid of ich. The ich was gone and the tank had became over run by cherry shrimp. The tank is 2 wpg w/ co2