The Nu-Clear Model 1522 Extension Kit doubles the height of the Nu-Clear filters, allowing the use of two cartridges and twice the amount of carbon. The extension kit for the Inland Seas Nu-Clear Model 522 Canister Filter, 100 Micron Cartridge & Carbon Filter includes the extension housing, 18 sq. ft. 100 micron poly-screen cartridge, and a 1.5 lb bag of premium Inland Seas Marine and Reef activated carbon. It expands the capability of the Model 522 Canister Filter so it can handle freshwater and saltwater fish-only tanks up to 180 gallons and ponds up to 600 gallons.
All extension kits include the body extensions, stainless steel band clamp, 1" mpt port plug, and a cartridge coupler. Extensions kits include a plug for the redundant inlet on the bottom filter. It is not recommended to mix different types of cartridges or media (i.e. Do not use a Model 522 with Extension Kit 1547, only use the Model 522 with the 1522 Extension Kit)