Chlorine Removal? You Must Know Calcium Sulfite!

Municipal tap water is disinfected with chlorine to suppress pathogens, yet residual free chlorine causes unpleasant chlorine odor, bad taste, and irritation to skin and hair during showering. It also damages downstream RO membranes, ion exchange resins and sensitive water treatment components.

Traditional activated carbon relies on adsorption, which loses capacity rapidly under hot water and high flow rates. KDF media has higher cost and limited flow tolerance. Calcium sulfite balls (CaSO₃) become a reliable, cost-effective dechlorination solution by chemical reduction, not physical adsorptionDriplife.

How Calcium Sulfite Balls Work

Calcium sulfite is a reducing agent. When water flows through the media bed, an instantaneous redox reaction happens between CaSO₃ and free residual chlorine (HOCl, ClO⁻, Cl₂):

CaSO₃ + HClO → CaSO₄ + Cl⁻

Residual chlorine is converted into harmless sulfate and chloride ions. The reaction takes only 0.1–0.2 seconds, so it works well even with short EBCT and high flow rates. The byproduct calcium sulfate is non-toxic and naturally present in water, no harmful secondary pollutants are generated.

Note: Calcium sulfite targets free chlorine. It is less effective for chloramine; multi-stage design is recommended for water with chloramine disinfection.

Core Advantages of Our Calcium Sulfite Balls

✅ Ultra-fast dechlorination Over 99% free residual chlorine removed in split seconds, suitable for high-flow point-of-use filters. 

✅ No regeneration, no backwashing Once exhausted, simply replace the media. No chemical regeneration, no complicated backwash piping, low maintenance for small filter systems. 

✅ Long service life & high capacity Sintered spherical structure slows down dissolution uniformly, avoids powder leakage and channeling. Consistent dechlorination performance through the whole service cycle. 

✅ Wide pH working range Works steadily across common tap water pH range, compatible with most municipal water supplies. 

✅ Flexible size options & OEM support Available sizes: 0.5–1 mm, 1–2 mm, 2–3 mm, 3–5 mm. Custom purity, packing, cartridge filling service available for filter manufacturers.

Typical Applications

• Shower filters & bath filters (most popular application)
• RO system pre-filter, protect reverse osmosis membrane from chlorine oxidation
• Water purifier cartridges, under-sink filter modules
• Hot water heater, spa, small swimming pool pre-dechlorination
• Drinking water equipment, vending water machine pre-treatment
• Water treatment EPC projects as dechlorination polishing media