lando, you don't advocate a top ?
Correct. Going "topless" allows for better gas exchange between the tank and the air. It will also help in keeping temp down. The biggest benefit for me is that I get a lot better light penetration into my tank. My corals love me for it. Glass tops themselves and the salt creep they collect can really decrease the amount of light into the tank. Evaporation rate will be higher so FW
topp-offs will need to be done more, but this is a good thing.