Skimmers

Anyone have experience with AquaC EV180 skimmer? I'm using the required Mag
7 pump. Makes nice foam but next to nothing gets up into the cup. I have
adjusted the waste gate from wide open which sets the water level to 1 inch
below the reaction chamber as per instructions. and I have closed the valve
to raise the water level to half way up the reaction tube and it still
doesn't collect very much foam at all. air valve is wide open. skimmer has
been running for over 3 months now. the only thing I get is a thick crud
build up in the riser tube, but not nearly enough cup crud. Any help as to
what I may be doing wrong would be greatly appreciated. I emailed AquaC over
5 days ago and not even a reply yet. While we are on the subject which
skimmer do you like better, Precision Marine Bullet-2 or ETSS Evo 750? I
need short height for cabinet fit. Unit must be out of sump and elevated on
stand to allow return to be at or above normal sump water height. I run a
large sump with a 10" high water line. Can I adapt an injector like a PM
skimmer to my AquaC?
John