Thanks for making things clearer in my mind with regards to whether or not the second frog could be of a different species if it's going to be in the same terrarium (no, for now at least).

Space is one of the main reasons I said captivity and life in the wild were different ball games (others include things like variation gradients in the environment). You can find several species of frogs even within two feet of one another, but they're not stuck together forever. The same goes for multiple frogs of the same species.

I'm guessing success with multiple species tanks depends on the species, the owner's care, the set up and the individual (leopards are notoriously skittish, but mine seems to have gotten used to me enough not to care much about hiding from me no matter what I do... unless I really [accidentally] scare the **** out of it). I'm actually scared this could change with the introduction of a new frog.

Just to clarify, I do not dispute the idea that toads have toxins, just the idea that all frogs do (or enough of them to make a generalization).

Do you guys have any suggestions regarding water management? What's the fastest way / set up you've found for the water changes. I have enough other animals to take care of that streamlining the water changes for my frog(s) would make a difference in deciding whether or not to house the frogs together. The same goes with the rest of terrarium care, if you have any tips.