This is a small skimmer I used many years ago. Had a fancy way of recirculating the water to maximize contact time. I believe it needs a small pump, perhaps a needlewheel style. If you don't use it a pump you could always convert into a calcium reactor or flowthru reactor of some type. The acrylic seems to be pretty high quality. Pickup is in Wakefield MA. Please PM me with a phone number if you are interested. Please be specific about what thread you are replying to.