Good point! I'll definitely have to look at selling the light down the road, even the full hood if someone needs one. Sounds like your heater experiment was a good one, and since I don't want to freeze out my tank either, I'll definitely plan to deal with the evap if I eventually ditch the hood and get new lights (I went ahead and got a Hygger ATO off Amazon... it'll be interesting to see if it works well and doesn't make me too nervous that it might fail in the "on" position... that would be a nightmare). We get pretty humid here in the summer too, but can still get snow all through spring, so it could be a while before top offs would slow down for me without an ATO.The good news is, there is always someone willing to buy a 2nd 3.0, so you can sell your light when you upgrade and make some money back. I sold mine for $180 with the brick to someone local. I'd have done $200 w/ shipping included to someone out of state. Like you I keep my house at 70F year-round when I had the hood it made my heater not have to run because tank temp was 78 and heater was set to 75-76. Once I got the screen top and the AI Primes, I unplugged my heater just to see how low it would get and it dropped all the way down to 72 before I decided that was enough of an experiment and turned the heater back on Evap is crazy, I'm adding about a gallon or so every other day right now, waiting for that humid summer weather to come back so it will slow down, lol.