Ok well heres the deal I have a 20 gallon tank (long) and its half land half water with a river running down the land part so its a nice set up so I want something cool to put in it basically...how many? what? anyting I should mix? shouldnt mix? and also I would like something that would eat feeder fish and things like that. I currently have had a whites tree frog for 4 years now and hes doing awesome in his 20 tall tank so I wanna make a new tank so any advice would be sweet thanks

