I was wondering if there was a native fish that would eat algae in a 20 u.s. gallon aquarium. Also it would need to only eat algae and/or meat (bloodworms, etc.) because this is for a planted aquarium kept at room temperature. Also right now there are a black crappie and a warmouth sunfish in the 20 gallon ( don't worry, I know that they need a bigger tank. I have a tank for them to go into when they are bigger. the 20 is a growout tank for those fish) I have tried american flag fish but i never have been able to keep one (even though i have tried to keep one, that one died 2 days later). Thank you for posting on here