Aquarium Water RO System Filter Kit AFK-Psi replacement filter kit - for ARO-Psi systems 1-micron sediment filter 1-micron carbon block filter Full size DI filter Inline DI filter (1/4-inch quick connect) Replaces RFDIFK filter kit for Reefmaster Auqarium RO/DI systems Replacement filter kits include all filters (excluding the membrane) used for the ARO-Psi and Reefmaster RO/DI systems. Dual DI filtration ensures the purest water and longer filter life. Quality customer support before and after the sale! Replacement membranes and other parts are available - check out our eBay Store. Love our solutions, love our products, love our support. Love your water!