Manufactured by AMPAC USA, this 4″ x 20″ cartridge turns flat, demineralized reverse osmosis output into balanced, great-tasting drinking water – the mineral content and pH your household water is missing after RO filtration strips it out.
What This Filter Does
Reverse osmosis membranes strip nearly everything from water – including calcium, magnesium, and potassium that your body uses. The result is pure but slightly acidic water, typically sitting between pH 6.0 and 7.0. This 4″ x 20″ alkaline filter restores those minerals and raises pH to the 8.0-9.5 range before the drinking water reaches your tap.
Media and How It Works
The cartridge contains a blend of calcite, coral calcium, magnesium oxide, and tourmaline mineral media. As water passes slowly through the bed, it dissolves trace amounts of each mineral into solution. Calcium and magnesium harden the water slightly, potassium rounds out the mineral profile, and the alkaline media neutralizes residual acidity. The result is noticeably cleaner-tasting drinking water compared to flat, demineralized RO output.
Why It Matters for Drinking Water
Flat-tasting RO water is the most common complaint homeowners raise after installing a reverse osmosis system – and it’s a direct result of stripping out minerals along with the contaminants. Re-mineralizing the drinking water with this alkaline filter restores the taste profile most people associate with quality bottled or spring water, without giving up any of the filtration performance upstream.
Installation
Install inline on the RO output line, after the post-carbon polishing stage. If your system includes a UV disinfection unit, place this filter before the UV lamp – UV works best on water that has already been polished and pH-adjusted. The 4″ x 20″ housing fits commercial RO systems and larger whole-house setups that use big-blue or equivalent housings rather than standard 10″ cartridges.
Replacement Schedule
- Replace every 12-24 months under normal residential use
- Higher-flow commercial systems may need replacement closer to the 12-month mark
- Higher source water TDS accelerates media consumption – shorten the interval if your feed TDS exceeds 500 ppm
- A drop in pH or flat taste are the practical signs the media is spent
Specifications
- Size: 4″ diameter x 20″ length
- Output pH range: 8.0 – 9.5
- Minerals added: calcium, magnesium, potassium
- Compatible with: RO post-treatment, commercial water treatment systems
- Manufacturer: AMPAC USA, Woods Cross, Utah
Related Resources
- Residential RO Systems — complete lineup of home water purification systems
- Replacement Parts & Filters — maintenance kits and consumables for your system
- Contact Us — help with installation, sizing, or replacement parts
AMPAC Water Systems designs and manufactures advanced water treatment solutions for commercial, industrial, and municipal applications. From RO systems and PFAS removal to zero liquid discharge and smart water technology — engineered for your needs.
