Hi, I've had my Whites tree frog for almost a year now, and I have his tank set up with just plain Eco Earth sitting on the tank floor ( I replace it every 2 months or so ). I want to improve my setup, so I'm researching how to make a false bottom. There seems to be a lot of conflicting information out there though, and a lot of the how-to links on the forum here are giving me 404 errors.
From what I understand, a false bottom is set up like this:
PVC pipe with notches cut in it to support the eggcrate, the notches are to let water flow through
eggcrate on top of the PVC
a screen or mesh on top of the eggcrate, to let water in but stop substrate from falling through
substrate like eco-earth on top

my question is about draining the water, and the setup of a pond (or a half-aquatic tank) using the false bottom.
it is my understanding that, to create a pond, you can cut away a section of your eggcrate, and lay the mesh over top, and then put rocks (large & smooth so they won't hurt the frog) over that instead of substrate, to create a dip in the tank that gets filled with the water from the drainage layer that is underneath the eggcrate. then, once the drainage layer gets full enough that it's soaking into the substrate which is bad, you can get a pump and drain out the extra water.

1: the frog needs dechlorinated tap water to soak in. So, if the pond is filled with the water from the drainage layer, which comes from the misting water, which is distilled how does that work? how will the water in the pond be acceptable for the frog? wouldn't it get gross from sitting in the drainage layer?

2: if there are rocks there, will the water even flow in-between the drainage layer and the pond? Should it?

3: how will there be enough water for the frog if the water can only be as high as the eggcrate? what about when the water needs drained and there isn't any water in there for a while until misting builds it back up?

i'm very confused about this. let me know of any of my questions don't make sense, or if I have something wrong here.