just thought i'd follow up on this thread.
Got my replacement cup from Aqua-Digital without any fuss. So that was great they followed up on a problem quickly. Ray (goreef.ca) and Aqua-Digital was great.
The recommended water depth for this skimmer is 180mm (7") to 240mm (9.4"). I started off with a 9" depth because that was the natural depth of my sump w/o any raising of the skimmer. I have a ATO system in place to keep the water at a consistent depth (very crucuial for efficient operation of skimmer - imo). I find that for me the optimum depth is about 7.5 inches. At 9" - the gate is wide open and if you have anything that cause the skimmer to react (like using putty to put in a bunch of corals) - the skimmer overflows and you can't do much about it (short of turning it off an emptying the cup). I ran it at different depths and just found 7.5 inches seems to be the best depth. The gate is about 1/2 opened and i have a fair bit of control over how dry/wet i want to run it. I noticed if you run the gate wide open there is a bit of turbulence in the water under the pump (from looking at the movement of the bubbles) so i think that reduced that contact time the water has and in effect is less effective (in a very minimal fashion).
A useful tip i would offer is to mark off a spot on the control for the gate valve and the direction of control. I keep bumping the control when i take the cup out and the reference lets me know what my setting was before:
IMG_4767 by [url=http://www.flickr.com/people/93342758@N02/]
No review of a skimmer would be complete without a picture of skimmate in a collection cup so here it is:
IMG_4766 by [url=http://www.flickr.com/people/93342758@N02/]
I consistently get a dark skimmate on a daily basis. I'm a bit lazy so i only empty the cup ever other day or so.
So all in all i would highly recommend this skimmer. The pump is whisper slient and powerful. The design of the skimmer is great - the acrylic used is very thick and high quality.
The distributers and retailers give great service and fixed a shipping defect problem right away.