What does an alkaline filter add to RO water?
Alkaline post-filters contain mineral stones or ceramic balls releasing calcium, magnesium, and potassium into the permeate. This raises pH from the typical RO permeate range of 5.5 to 6.5 up to 8.0 to 9.5. The added minerals also produce a measurable negative ORP (oxidation-reduction potential), which proponents associate with antioxidant properties.
Is alkaline water from a filter the same as ionized water from an electric ionizer?
No. Electric ionizers use electrolysis to separate water into alkaline and acidic streams, producing higher and more consistent ORP values. Alkaline filter cartridges raise pH through mineral dissolution, which is a passive process. Both produce high-pH water, but an ionizer gives more precise pH control and typically stronger negative ORP.
Who is an alkaline filter cartridge best suited for?
Health-conscious consumers who want remineralized, slightly alkaline drinking water without investing in an electric ionizer benefit from this cartridge. It is also a practical choice for RO system owners who find pure RO water tastes flat, since the added minerals improve taste and mouthfeel noticeably.
How long does an alkaline filter cartridge last?
Replace every 12 months under normal residential use. The mineral stones dissolve slowly as they raise pH and add minerals, so higher water volume speeds exhaustion. Monitor output pH with a meter or test strips. When pH at the tap drops below 7.5, the cartridge media is nearing depletion.
Does an alkaline cartridge work without an RO membrane upstream?
It will function, but it is designed to treat already-purified RO permeate. On unfiltered tap water, the mineral stones would not significantly alter pH because the incoming water already contains minerals and buffering capacity. The cartridge is most effective and has the longest service life when installed as an RO post-filter.