Alkalize/Ionizer, Mineralizer & Oxidation Cartridge

Reverse osmosis water is clean, but it can taste flat. RO removes nearly everything dissolved in water, including the calcium and magnesium that give water its body, and the water that comes out is often slightly acidic. Soft, low-pH well water has the same problem, and it can be corrosive to plumbing.

The Crystal Quest Alkalize/Ionizer, Mineralizer & Oxidation Cartridge puts minerals back. It is an alkaline mineralizer cartridge filled with a blend of calcite and magnesium oxide. As water flows through, the media slowly dissolves into it, adding minerals and raising pH, in a drop-in cartridge for four standard housing sizes.

At a glance

• Adds calcium and magnesium back to RO water or naturally soft water
• Raises pH and alkalinity, making acidic water less corrosive
• Natural mineral media: a blend of calcite and magnesium oxide
• Typically 12 to 24 months of service in every size
• Four drop-in sizes, 0.5 to 6 GPM, for countertop, under-sink and whole house housings

What you are looking at

Each cartridge is a polypropylene shell filled with the mineral blend, held in place by a polypropylene expansion pad and followed by a spun polypropylene post-filter, which catches any fine mineral particles before the water leaves the cartridge. Polypropylene end caps and a Buna-N top gasket seal it in the housing. Because the media dissolves as it works, the bed slowly shrinks over its service life. Each end cap has 1-micron pads behind its openings.

How an alkaline mineralizer cartridge works

Why RO water and soft water run acidic

Pure water has almost no buffering capacity. Carbon dioxide from the air dissolves into it and forms carbonic acid, which pulls the pH down. Hard water resists that drop because its dissolved minerals neutralize the acid. RO water and naturally soft water have little of that mineral buffer, so their pH falls easily.

Carbonate minerals neutralize the acid

Calcite and magnesium oxide react with that acidity. As they dissolve, they neutralize carbonic acid and leave behind bicarbonate alkalinity and dissolved calcium and magnesium. The pH rises, and the added alkalinity acts as a buffer that helps hold it there, which makes the water less corrosive to pipes and fixtures.

Self-adjusting by nature

Carbonate minerals dissolve fastest in acidic water and slow down as the water approaches balance. More acidic water takes up more mineral; water that is already balanced takes up little. That is why the cartridge does not promise a fixed output pH: the result depends on the water going in, its contact time and its flow.

What it reduces

Primary targets:

• Acidity (low pH) in reverse osmosis water and naturally soft, low-mineral water
• The corrosiveness of acidic water toward pipes and fixtures

Also reduced: the flat taste of very low-mineral water. The cartridge does this by adding calcium, magnesium and alkalinity, not by removing anything.

Not designed to treat: it is a mineralizer, not a filter for contaminants. It does not remove chlorine, chemicals, lead or other heavy metals, fluoride, nitrate, arsenic, bacteria or viruses. It also adds hardness, so it is not meant for water that is already hard or already high in pH. For chlorine and metals, put a SMART Filter Cartridge ahead of it.

Is it right for my water?

• After reverse osmosis: the most common use. Put the minerals back into RO water as the final stage.
• Soft or slightly acidic water: raise the pH of naturally soft, low-mineral water at a drinking water tap or in a cartridge system.
• Strongly acidic well water for a whole home: talk to us about an acid neutralizing whole house system, which holds far more media than a cartridge.

This page sells the four drop-in sizes. Crystal Quest also makes a sealed inline alkaline mineralizer cartridge for RO systems and water coolers, and an Alkalizing + SMART Filter Cartridge that adds carbon, redox and other filtration media to the mineral blend.

Why Crystal Quest

• Natural mineral media, described exactly: calcite and magnesium oxide.
• Honest about results: no promised output pH, because your incoming water decides it.
• Three formats (drop-in, sealed inline and SMART combination) so the mineral stage fits your system.
• Over 1,000,000 people served since 1994. Crystal Quest builds under ISO 9001 quality management, has made water filtration in the USA for over 30 years and offers lifetime support by phone, email or chat.

Where it fits

• Countertop and under-sink systems that take the 2-7/8" x 9-3/4" size, as the last stage.
• Whole house cartridge systems with slim 20" or Big Blue housings, after the filtration stages.

Choose the size printed on your current cartridge or in your order history: 2-7/8" x 9-3/4" (CQE-RC-04058), 2-7/8" x 20" (CQE-RC-04091), 4-5/8" x 9-3/4" (CQE-RC-04092) or 4-5/8" x 20" (CQE-RC-04093).

Common questions