I've seen tanks where species were mixed, quite often. And the only times I've seen them work is when it was done by very serious senior hobbyists, where biotopes had been created in very large tanks, and where it was made sure that all the frogs in the tank were from the same area, and their native space was respected (arboreal space for species X and terrestrial space for species Y). But obviously, we're not talking about this here...

Like Tony said, you have frogs that come from all over the globe, and these frogs have very different needs. Now if your frog will not disappear because they will feed on the smaller ones (some frogs are cannibalistic and will simply eat a smaller version of themselves or another species), they will slowly die because of being in a tank with wrong climate for them, or from slow poisoning as toxins from other frogs will end up being lethal for them.

So take the opportunity to build a few new tanks... And we are here to help you make these new tanks perfectly suited for your frogs... Just ask us!

Eric