Importance of filtration in a water feature?

[Dragoon]

I set up a terrarium just to grow plants but i am now considering adding red-eyed tree frogs. I didn't set up any filtration in the false bottom but i do have plants in the water as well as root systems from the terrestrial plants that developed through the false bottom in the water. Even if i provide nitrogen fixing bacteria with suitable water flow to break down ammonia, a standard water bowl for the frogs to soak in, and water changes could the lack of filtration cause any toxic build up that would be detrimental to the frogs?

[froggsong]

Unless the frogs use the water for a toilet, you have fish, or you're adding ferts, I doubt that you'll see considerable ammonia levels from adding the frogs. As far as I know, they use the bathroom pretty much wherever, so you'll get some in the water from time to time, but I don't think that they'll do it all the time. If the tank has been set up for any real length of time, you're biological filtration is already going on. Do you have a pic of the current water feature? Is there a waterfall? Moving water? As long as it's not stagnant, I think you'll be fine, and you shouldn't have to add another dish unless it's very small.

[beckdg]

should be good as long as it's moving.

[Dragoon]

thanks. i know tree frogs like to soak occasionally and wanted to know the risk of them using the water as a toilet.