Aquatic Life RO Cartridge Set of 3 - (1-DI Color Changing Mixed Bed Resin, 1-Sediment Cartridge, 1-Carbon Cartridge)

I've been using the rodi buddy for a couple years now. It's perfect. It's small, easy to change filters, cheap compared to what you see on BRS. Take maybe 45min to fill a 5 gallon bucket. Always reads 0 on the TDS meter. When you see 1 on the TDS meter it is time to change the charcoal filter. I need to mention the TDS meter is sold separately but should be bought when purchasing the rodi buddy. Prestine water quality and simple functionality.

This product is a lifesaver for improving water quality. We have saltwater aquarium with fish and live corals which are extremely sensitive to water quality. These filters have kept our aquarium healthy and happy by completely clearing the water of heavy metals, chlorine, and calcium. The filters work best if you slowly force water through them, so be patient. But I assure you that the quality is fantastic.

deionization filter turned completely brown after about 70 gallons

Have had this filter for quite a while. Once my second set of filter cartridges. Consistently give me 1 TDS output. Combine that with the price and it's hard to beat. Its only 50 gal per day, but I have 3 nano reef, so it's not a problem for my needs.

Simple to assemble.