Calcite Media for pH Correction: When and How to Use It in Water Treatment
Acidic water is a common problem in many residential, industrial, and municipal water systems. Low pH not only causes corrosion in pipelines and fixtures but can also leach metals like lead, copper, and iron into the water—posing serious health risks. That’s where calcite media comes in.
Calcite is a natural, crushed and screened calcium carbonate (CaCO₃) media used to neutralize acidic water. It is one of the most popular pH correction filter media used in water treatment worldwide.
What Is Calcite and How Does It Work?
Calcite is derived from high-purity limestone and is composed primarily of calcium carbonate. It reacts with acidic water to raise its pH naturally:
CaCO₃ + H₂CO₃ → Ca²⁺ + 2HCO₃⁻
This chemical reaction:
Increases water pH
Adds calcium to the water (beneficial for health)
Reduces corrosion potential
✅ Calcite is a self-limiting media: it only dissolves until the water reaches a non-corrosive equilibrium pH (usually around 7.0 – 7.5)
When to Use Calcite in Water Treatment
1. If Water pH Is Below 6.8
Water with a pH lower than 6.8 is considered corrosive. Calcite for acidic water is effective when the pH ranges between 6.0 and 6.8.
2. For Home or Commercial Use
Calcite filters are widely used in:
Homes with well water
Residential RO pre-treatment
Water softeners
Food and beverage applications
Boiler feed systems
3. In Combination with Corosex or Magnesia
If pH is below 6.0, calcite alone may not be sufficient. It can be mixed with Corosex (Magnesium Oxide) to increase pH more aggressively.
Benefits of Using Calcite Neutralizing Media
| Advantage | Description |
|---|---|
| Natural | Non-chemical method of pH adjustment |
| Self-regulating | Won’t over-correct pH |
| Easy maintenance | Media only needs periodic topping up |
| Affordable | Low initial and operating cost |
| Safe | Adds calcium, no harmful by-products |
How to Use Calcite in Your Filtration System
1. Filter Tank Setup
Calcite is typically used in a pressure vessel with an underdrain and top distributor. Water flows through the bed of calcite and neutralizes as it passes.
2. Backwashing
Though calcite dissolves over time, occasional backwashing is needed to remove fines and prevent channeling. Backwash flow rate is approx. 10–12 GPM/ft².
3. Media Replacement
Calcite dissolves gradually and needs to be replenished every 6–12 months, depending on water chemistry and flow rate.
Typical Specifications for Calcite Media
| Parameter | Value |
|---|---|
| Color | White or off-white |
| Composition | CaCO₃ (95% min) |
| Effective Size | 0.4 – 0.6 mm |
| Uniformity Coefficient | ≤ 1.6 |
| Bulk Density | 1440 – 1600 kg/m³ |
| Solubility | Gradual, based on water pH |
Applications Where Calcite Is Used
Borewell water treatment
Low pH RO pre-treatment
Residential water filtration units
Rainwater harvesting recharge filters
Industrial demineralization plants
Municipal softening units
Why Choose Starke’s Calcite Media?
Starke Filter Media supplies high-purity calcite media sourced from quality limestone mines. Our media is:
✅ AWWA B100 & IS 8419 Compliant
✅ Uniformly sized with low dust content
✅ Available in 25kg, 50kg, and jumbo bags
✅ Ready for global export with palletized, shrink-wrapped packaging
Conclusion
If you’re dealing with acidic or corrosive water, using calcite media for pH correction is a simple, cost-effective, and reliable solution. Whether you’re treating water for residential, industrial, or commercial use, neutralizing media like calcite ensures that your water is safe, non-corrosive, and balanced.
Need premium-grade calcite for your project?
📩 Contact us at info@starkefiltermedia.com
🔗 Visit: www.starkefiltermedia.com