ha i think you and i had a lengthy discussion back and forth on this. maybe....
after i changed from the mag 9.5 to the quiet one 2200 it does go idle from time to time. the water level in the skimmer compartment is not dependent on top or or evap. my return pump is the lowest water level in the sump.
i did some research and found a thread in another forum thats pretty much dedicated to this skimmer. i had mine setting in 10" of water i made a quick stand and now its just over 8" ill run it like this for a bit to see whats up. then ill make it 9" and see how that goes.
because im thinking about a possible upgrade in tank size i want flexibility with my skimmer. i really wanted to get a brand name skimmer like the vertex in-100 but if i do the tank swap i want a skimmer that can handle the extra volume of water and still be a bit +1 on size. this is the skimmer that i have now... 150 Gallon Fresh Saltwater Fish tank Protein Skimmer | eBay
it was priced right when i was looking to buy a skimmer.
i suppose when it comes down to it, i have very little experience with protein skimmers so i dont know whats right and whats not. i see some people have green skimmate and some have varying shades of brown. mine is brown and i try to get the darkest brown i can while still having to empty the collection cup once every week.