For a while I've been working towards the creation of a small 10 gallon desktop terrarium that had many environmental needs built in. I see many systems, small or large, that need other devices which take up more space than the terrarium itself. To work on my idea I used a 12x12x18 exo terra.
There were some of my issues for design.
1. Internal cool lighting which would allow plant growth, but not heat up the air in the tank. For this I used seven 9.5inch old style 12v waterproof LED strips. Unlike the newer LED lights that are brighter, but make more heat, these stay cool and 7 of them give me more light than a 14w CFL. Since they are inside the tank, I don't need a huge light fixture above the tank. Also since they are not hot, the frogs can't burn themselves.
2. I also wanted blue night lighting to simulate moonlight and help the vegetative state for plants. This was resolved as part of my air circulation system.
3. Having air flow through the tank was an issue since I didn't want to have stale air in the tank, creating bacteria. While internal air-circulation was considered, it sometimes allows for bad air to simply build up in the tank. I also wanted to ensure the temp in the tank was the same outside the tank. So I got a cheap laptop cooling system that uses three 5v fans with blue LEDs built into them. The air get sucked in from the top and blown out the front vent on the tank. In the future wire mesh will reduce the circulation I'm getting now, which is enough that I can feel the air coming out the front.
4. Keeping the tank humid was a big issue. Air flow to the outside reduced this. But a quick heavy rain every now and then would keep things damp and clean off the plants. So using a spray pump and four misting nozzles, I build a system to suck the water from the bottom of the tank and recirculate it at about 3GPH. The result was loud and now as fine a rain as I hoped, but still better than nothing.
Anyway watch the video and see what I built after Christmas. Happy New Year!