This is challenging. The only chamber that stays consistent (without ATO which may could solve the problem) is the entry chamber where I have the filter roller. Between that chamber and the middle refugium section is a baffle that can be raised or lowered (currently all the way down) Unfortunately my drains are hard plumbed so my filter roller would be a PITA to raise up. The 3 chambers on the right fluctuate with evaporation together. Any suggestions are welcomed and appreciated!!Your skimmer should be in a chamber where the water level is constant and not going up and down. If your sump is set up correctly the water level should only go up and down in the very last chamber when you have your return pump. For your skimmer to stay dry all night and then start overflowing that badly again today, I would say it is something you are adding to the tank. Did you pour your top off water directly into the same chamber as the skimmer?
Currently my tank is about 3 weeks old with only 2 clownfish. So not much in that area to skim I guess.