Help with my EV-180 Skimmer

Thanks coral reefer, as soon as i did some minor mods, it worked fine. Skimed good for about 3 inches of skimmate, now i only see some foam every now and then, its not always foaming, is this normal?
First time i have a tank setup with a refugium, so im thinking that really has to do alot with how much can be skimmed.

 

Mine always foams but does not always make it up to the top of the cilinder.
Is the foam white or is it dark. If white there isn't all that much to be filtered out anyways as the bio load is not that large. I believe that is what i'm going through with the 280gal of water. 200lbs LR, 200lbs LR and only 11 baby blue green chromis. Not much ammonia in there yet