I have been running mine on a 100 wal mart airconditioner turned chiller. Lots of DIY info around on the subject. Even with 2 1ks i can draw the water down into the 50's. Also, just because you can put them inches from your plants doesn't mean that you should! without some distance, the hot spots can be brutal on your girls. It literally only takes a few inches closer to make up for the loss from the water and glass.