Nano Skimmer

[rocketlily]

I am new to SW and my tank is now 48 hrs old. It is 20 gal, with 20 lbs live rock (Fiji) and 20 lbs. sand. I have a 20,000K Metal halide light, Hydor Koralia circulation pump, submersible heater and a Rio Nano Skimmer. The temp fluctuates between 24C-27C, Salinity is 35, PH 7.9, Nitrates under 5, Nitrites less than .1, Ammonia 6.1 and Phosphate .5

Of course I'm watching every hour to see if anything new has developed (Only 1 little clear worm coming out of a hole approx 3/8" long,so far). My problem is understanding the Nano Skimmer. I finally have the bubbles climbing up the tube and dumping into the collection cup, but should the collection cup also be filling with water at a rate of 1/2" every 1/2 hour. Am I supposed to let the water level in the collection cup fill up and flow back down the tube. This is very confusing and I hope someone can shed some light on this for me.