about 2.5 gallons per frog. they like company so the minimum is 2 in a 5 gallon. i prefer a species only tank. theyre hard to feed and you see them more this way. good tankmates are mid to top dwellers that are slow eaters. bettas can be good tankmates but must be docile. too small of a fish can be eatin. a good diet is the amphibian food at petsmart that i forget the name of (haha) just look it up on there site (some wont eat these), frozen bloodworms (ocassionally), and frozen brine shrimp. make sure to have a tight lid but also make sure they can get to the top to breath. i like reptile lids with the top cut to fit the filter snug. i have a 10 with 2 right now i plan on getting 2 more but new adfs must be quarentined for a minimum of 3 months bc of a highly contagious fungus.