I have an older aquac skimmer (I am pretty sure it is a 180). It is the one that does not have the valve on top. It is running on a rio 3100 pump and it does not seem to make a lot of foam. The foam typically is not up the neck at all. It does extract about a cup of tea colored water weekly, but most of the downdraft, becket, and recirculating skimmers I have seen seem to always have a neck full of foam. This is running on a 75 gallon display with a 20 gal sump and a 25 gal refugium. Any advice on this would be really appreciated.