Somebody please help me figure out this PM Bullet-1 skimmer!

[Delphinus]

Ok, so I've finally been running my PM Bullet-1 for about a week and a half now.

So, what a cool skimmer. Pulls out wicked amounts of foam, but I'm noticing a phenomenon I don't like too much. The instructions say to adjust the output valve, so that the water is about 1/3 up the way of the reaction chamber. Then open the air, and adjust both valves so that the water/air interface maintains steady at about 1/3 up the way of the reaction chamber.

What I find is, the water level steadily drops and drops and eventually is all the way down to the skimmer exit. So after about a couple of days, realistically, the skimmer has shut down. I find if I take the skimmer over to the bathtub and give it a real thorough cleaning and scrubbing, and put it back on, then it's back to the effective skimming again, but only for a couple of days.

Ok, so, cleaning the skimmer like that, is just NOT going to be an option. Forget it! Everytime I do that I scratch the bathtub up a little more. Once a month, I can live with, but not several times per week.

...

So what's the problem here? Why does the water level fluctuate so badly? Do I have a bad pump? Do I need to make my exit pipe come up to the top of the box, so that the water level can stay constant maybe?

Can people who have HSA, bullet, downdraft, etc. type skimmers, PLEASE post some pictures of their setup so I can get some ideas maybe on how to improve my plumbing? I'm at my wit's end!!

(Oh BTW the pump is a Mag12.)