Quote Originally Posted by SDballp View Post
i think they mean not to have any water ever come in contact with the UTH not that water cant be inside the tank above it

again i could be wrong but the extra water evaporation seems to help with humidity
No, they mean don't put the water in the hot end of the tank or over the UTH. This is just a precautionary measure because without a thermostat, the glass underneath is hot and if the water spills on it, it can cause the glass to crack. Kinda like when you put an ice cube in warm soda you can hear that little "CRACK" when it begins to melt.