The above tank is a 40 breeder with screen top. On top of the screen is a sheet of plastic shelf liner to hold back some humidity. Holes have been cut to allow the UVB (5.0) coil light and incandescent (40w) heat light to shine down. The Build... On the very bottom outside is a small sized under tank heater (more on that later). Next, inside, is 2" of pea gravel. This is to allow water to drip away from the soil above. A folded layer of nylon screen to fully cover the gravel. Next for my substrate, "Play sand" is supposed to be cleaned and not toxic, 50/50 mix organic potting soil and sand. This I put in at an avg depth of 3-4 inches. In this tank I have 1 Pathos plant, they are hearty and take a bit of doing to kill. Next went the primary log with a deep cave in it. This is the main support for other smaller pieces. In the back in a few rocks directly over the UTH. The UTH disperses it's heat into the rocks and acts as a low heat emitter for possible cold snaps. The UTH also heats the water accumulation under the soil so it evaporates up to the soil. I have a digital thermal and humidity sensor dead center on the lit covered by the plastic so it only reads the tank below. Lara and Bluegenes live in this tank. This is a similar build on a 20reg screen top tank. Housing a singe female (Oushi) as she really doesn't play well with ANYTHING... My humidity is maintained at 55% with lights on and 75-80 with lights off. I have 1-2" of standing water under the soil in the gravel that is heated by the UTH, without the UTH this would be risky as things could grow and smell bad. With the heat I have not had any trouble with smell or growth of nastiness. My Day temp runs 78-82 and night temps run 72-75. My room is kept warm so these tanks do not see a lower night time temp. Water is sprayed over the pothos leaves in the AM and PM, most swifts are "dew lappers" and don't drink from a standing water bowl. I am working on a small shallow lid or bowl help off the side of their logs to act as a leaf holding a small amount of water while misting, so it all doesn't roll off the leaves and soak away.