Collection: RO Filters

Fix the water before it reaches the tank

Tap water arrives with chlorine or chloramine, and depending on the supply it may bring phosphate, silicate and nitrate too. All of it either feeds algae or moves parameters you then pay to correct. An RO or RO/DI unit handles that at the source rather than in the display.

Choosing a system

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

Deciding on the DI stage

Three stages strip out most of what is dissolved in the supply but leave a small residual reading behind. For freshwater top-off and water changes on undemanding aquariums that is generally sufficient. Reef systems, and any tank where trace phosphate or silicate creates problems, are the reason to take deionizing resin.

Sizing and maintaining a unit

Read GPD as a ceiling rather than a promise. Those figures assume a specific feed pressure and water temperature; cold water and low household pressure each pull real output well below the number on the box, which is why booster pumps are common on well systems and cold-climate installs. Buy a TDS meter with whichever unit you choose, since nothing about spent DI resin is visible to the eye. Replacement cartridges and membranes are listed under Reverse Osmosis Media. Questions on sizing a unit? Email info@jlaquatics.com.