Some terrarium plans!

[Kurt]

You should'nt mix other species (not saying you were suggesting so), here is a list of more aquatic frogs:
1)Green Frog(Rana pipens?) only keep a pair at most
2)Indonesian floating frog(heard it somewhere but know nothing about it)

I would avoid most Ranids in a tank of this size, especially green frogs Lithobates clamitans melanota. These frogs have powerful legs that can launch them quickly away from danger. They can be skittish as well. You combine those two elements in a small tank like a 20 and you will have a bruised and battered frog. BTW. Lithobates pipiens is the northern leopard frog.

[Deku]

Sorry kurt. I always get those confused. :P And I know. But thats all I could think of that could go in that set up. I think maybe for the first year of their lives he could have one or a pair. Rather itd be one. Then hed need a 40breeder or a 55g.

[Kurt]

No need to apolgize.