Atlantic’s Waterscapes line Skimmers come in two sizes. The PS4500 Skimmer with 9" Weir Door opening is great for ponds and/or water gardens with a surface area up to 600 sq.ft. and a pump flow of 2,000 - 4,000 GPH. In addition to maintaining a beautiful, healthy pond, the Skimmer provides mechanical filtration for outstanding water quality. Each Skimmer unit includes removable lid, filter mat and basket and lifetime warranty on the enclosure.