A while back (around June or July '12) I had acquired a pair of FBTs, and they shortly after died, both in the same day. I really have no clue what happened to them, I only had them for about a week, and they just suddenly died one day. But I'd like to try again, and make some changes from what I did before.

I have a 29 gallon aquarium I'll be housing them in; it's more tall, but kind of long (30" long, 12" deep, 18" tall), probably enough space for 3-5 toads? I'd like to stick to a small number; I figure I COULD keep more in this size tank but 4 or so would be better for me to start with. I can always add more later if they do well

I'm going to create a paludarium style vivarium for them; possibly some live plants but undecided yet. Mainly I'm still deciding on the water depth. I Googled this and the answers were mostly "as deep as you want" but I feel too deep and they could drown. But I would like to use up some of the height the tank provides, so how deep would you guys say is the deepest you'd go? Somewhere I saw someone said 10 inches! How would the toad even stay at water level, if it wanted to? Are they able to float by themselves (silly question I'm sure)?

Anyways, I'm definitely doing something like 1/4 land, 3/4 water. There will be a filter, and I'll plan to do a small water change every day or every other day (it's possible my first toads died of toxin accumulation in the water, so I'd like to keep the risk at a minimum). I'm curious if anyone knows whether carbon (the filter media) gets rid of the toxins? If so, is it possible to keep some cold-water fish such as White Cloud Mountain Minnows in with the FBTs? I've seen some threads pondering the idea but none where people have actually tried, although maybe I'm looking in the wrong places. I just thought some fish would make a nice addition.

Thanks for reading! I may not start this up for a few more weeks, but I'll update when I do!