Hot Halides

[johnny rock]

you have glass seperating? do you mean you have a canopy covering your tank? If so, lose it! it will just keep heat in and it doesn't help with the gas exchange. It could also get hot and possible crack[depending on how high your lights are] not to mention you lose some of your lights penetrating power and you'll forever be trying to keep that glass clean.
evaporation is needed to help cool the tank and you can add more KALK if your evap, is good and a glass cover will not help this.