Yeah that's pretty cool, except you have to keep adding water all the time. I've seen those before and thought about using them. Mini swamp coolers, they are. The concept has been around for a long time, but not packaged so nicely. I've thought about getting one of those and rigging a small pump to pump the melted ice to an ice maker, then automatically the ice goes into the swamp cooler again. I gave up on the concept but I think it could be done with a little Mcgyver mentality.

You had to ask about the temp. Well you brought this on yourself, another thing for you to buy. The only true way to know if your temps are correct is to take the temperature of the leafs. The only way I know to do this is with a laser thermometer. The leaf temps should be under 80 degrees at all times, and that is always a little different than the air temps. How different? Anywhere from 3 to 8 degrees or something. Gotta keep the temps in the grow under 82 to be sure the leaf temps are under 80. This is how I figure out how far away I have to keep my lights. I raise them pretty far up, then take the leaf temps, then keep lowering the light, waiting a couple hours, then taking the leaf temp again until the leaves are averaging about 76.

Laser thermometers are anywhere from $25 plus shipping to $60 at a store.