I empty my collection cup about once a week. I do a full cleaning of the upper chamber at that point. Seems to collect fairly well. I use a prizm hang-on skimmer and when the water surface looks a little dirty I adjust the flow so the skimmer cup is half full of tank water. So the surface water cascades into the inlet. Sort of like an over flow box does. Within 15 to 20 minutes the surface is sparkling. You need to play with the valve to get the right balance. Too much and you break siphon, too little and inlet fills up. Once clear I turn it down to a moderate flow.
_________
Marty
72g Bow Front, 2x250w MH (10 hrs), 4x65 Act (14 hrs), 6xDual Moonlights (10 hrs), 300 gph from cannister filter and powerhead, Prizm hang-on protein skimmer, 50 lbs LR, CC Bed
Yellow Tang, 2 Clowns, Bubble Tip Anemone, 2 Yellow Tail, Humbug, White Spot, Ornate Goby, Emerald Crab, Sally Lightfoot Crab, 2 Blue Legged Hermits, 15 Scarlet Hermits, +Snails with no names (margaritas, turbos, astraeas) | 
skimmer has 1/4 inch of gunk...thats all 
alot for your help.
