Our RO/DI devices are for Reef/Aquarium fans who require simplest the purest of water and whilst Opposite osmosis isn’t sufficient. Opposite osmosis eliminates a big majority of TDS (general dissolved solids) however now not sufficient of it. TDS is can also be reduced to extraordinarily low ranges through the usage of a DI (deionization) filter out. With our programs, you’ll most often get ZERO to close ZERO TDS readings!!!