I have an AquaC EV-180 powered by a mag 9 and love it, its been by fare the best skimmer I have owned and seen in operation. It pulls a steady amount of skimmate out everyday and the only adjustments I have had to make were when I first set it up last march. I haven't touched it since other than to clean the collection cup, and I checked the injection nozzle about a month ago. I know a couple of people that have the HOB versions one has a remora and the other a urchin and both are very happy with their skimmers and neither is noisy. The urchin when we first installed it was a little noisy but after a week it was pretty much silent.