Aquatic Life Reverse Osmosis Deionization (RODI) 10" Color Indicating Mixed Bed DI Resin Cartridge 3-Pack. Filled with Resintech MBD-30-NG Nuclear Grade Mixed Bed Resin THREE Color Changing Mixed Bed DI Cartridges filled with MBD-30-NG Nuclear Grade Resin. Standard 10" cartridge housing - Designed for upflow applications to ensure the longest possible exposure time. Refillable. Twist-On Cap with Fine Filter insert and Sponge to prevent filter media flow out. Filled with color indicating MBD-30-NG resin to remove more TDS from membrane filtered water. Compatible with Captive Purity, Kent Marine, Seachem, Coralife, BRS, and most other residential or aquarium/hydro DI or RODI systems.