Collection: RO Filters

Start with water that has nothing in it

Tap water carries chlorine or chloramine, and depending on the supply it can bring phosphate, silicate and nitrate along with it. All of that either feeds algae or shifts parameters you then spend money correcting. An RO or RO/DI unit deals with the problem at the source instead of in the display.

Choosing a system

• Three-stage RO - sediment, carbon and membrane, producing RO water.
• RO/DI systems - the same stages plus a deionising cartridge, taking output closer to zero TDS.
• Four-stage RO/DI - larger housings with a separate DI stage, for higher throughput.
• Output ratings - 50, 100 and 200 GPD, quoted at the manufacturer's test conditions.

With DI or without

A three-stage unit removes the bulk of the dissolved solids but leaves a small residual reading behind. That is usually enough for freshwater top-up and for water changes on undemanding tanks. Reef systems, and anything where trace phosphate or silicate causes trouble, are the reason to take the DI stage.

Sizing and running one

Treat GPD ratings as a ceiling, not a promise. Those numbers assume a given feed pressure and water temperature, and cold water or low household pressure will both pull real output well below the figure on the box - which is why a booster pump is a common addition on well systems and cold-climate installs. Whichever unit you pick, buy a TDS meter alongside it: there is no way to tell by eye when a DI stage has stopped working. Cartridges and membranes are stocked under Reverse Osmosis Media. Questions? Email info@jlaquatics.com.