Up to 20,000 gallons. Maximum Flow of 7500 gph.The Ultima II is specifically engineered to meet the environmental demands of fish ponds. It uses tubular Bio-Media designed for high flow rates. Media comes in three different sizes with random lengths and diameters to avoid stacking. A patented backwash system keeps the media from clogging. Cleaning the filter is done by internal jets. The Ultima II is also the ideal filter for aquariums where very high flow rates are desired. The Ultima II is available in large industrial sizes. 2 Inchinlet/outlet(product code: AU50119) Item ships via motor freight directly from manufacturer. Customer service will contact via phone or email regarding freight quote.