Yes placing the water on the hot side increases humidity in our enclosures which are 10, 20, and 40 gallon tanks. I have no experience with t8 cages. No our water does not get too warm, it stays a few degrees cooler than the air directly above it and we frequently see our snakes drinking from and moving thru the water. If in doubt pick up a cheap thermometer in the aquarium section of Walmart and place it in the water. You change water and disinfect the bowls every day? Why? Don't you think that's a bit OCD?