I also have a 46 gallon, and with new skimmer (just in the tank one week), I emptied the collection for the first time today...BUT...I will be checking it much more often, like very 3 days or so. I keep the cup really pretty high in the chamber to get dry skim, and I found that after a week the collection cone was almost plugged with crud. Like I said, it's only been in my tank for a week, and I didn't think it would skim so well right off the bat (CPR bak pack, in case anyone's interested). By the way, after water change today it took off right away without a ton of adjusting!! We'll see how it goes in the future.
Lisa