I dont know if this is considered a paludarium since it is not that much water in there. Here's the info on the tank.
I siliconed a 1" layer of styrofoam on the back of the tank and then put Great Stuff over it. (i was afraid the GS will peel off easily without the styrofoam behind it)
Then i mixed peatmoss and coco fiber on that ACE concrete primer and binder. My first try i think i put too much peatmoss in there (it looked too dark for my taste) so i put a second layer on it with less peat and more coco fiber. The whole background was rock hard after 3-4 days.
I used the 'silicone + coco fiber' method on the lower part of the tank since ACE concrete primer isnt good underwater. Then i put a mixture of flourite and Amazonia Aqua soil under the water. (The aqual soil alone would be too compact and muddy, so i mixed the flourite to give the substrate some aeration)

as you can see, the area around the stump isnt finished yet, im in the process of pre-soaking the orchid mix and charcoal. It'll go in tomorrow. I put a layer of landscaping fabric under the fiberglass screen, just to make sure none of the substrate will go under the false bottom.

yes, the temp is 74 and 67 on humidity. that's because the top of my tank isnt finished yet, plus the misting system isnt hooked up also.

I have a canister filter that's running the water from the left side of the tank going to the right side. The temp and the humidity in the tank should go up once i hook up the inline heater to the canister filter.