Aquatic Life 10-Inch Color Changing MBD-30 Nuclear Grade Mixed Bed Resin DI Cartridge 3-Pack Bundle. THREE Color Changing Mixed Bed DI Cartridges filled with Our MBD-30-NG Nuclear Grade Resin: Opaque cartridge allows easy detection when color changing mixed bed resin is exhausted. Mixed be resin changes from blue to amber when depleted. Filled with Aquatic Life MBD-30-NG Nuclear Grade resin. MBD-30-NG resin is used as the final stage of filtration in reverse osmosis and deionization (RODI) systems - Cation and Anion resins (H+ and OH-) remove remaining total dissolved solids (TDS) from Reverse Osmosis (RO) membrane filtered water - 10 inch standard cartridge size - Cartridge housing shape lends itself to efficient water-to-resin contact - Top gasket on cartridge for secure fit in RODI systems. We have tested replacement cartridges from all manufacturers and believe ours are the best quality available. Features: THREE Color Changing 10-Inch Mixed Bed DI Cartridges filled with Aquatic Life MBD-30-NG Nuclear Grade Resin - Standard 10" cartridge housing - Designed for up flow applications to ensure the longest possible exposure time – Refillable cartridge with twist-on cap and 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. Item 330237.