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Calcite pH neutralizing filter


Calcite® is a crushed screened white marble media which can inexpensively be used to neutralize acidic or low pH waters to a neutral pH.

Calcite is a naturally occurring calcium carbonate mineral that plays a crucial role in various industries, including water treatment. It is a common mineral found in sedimentary rocks and is often the primary component of limestone and marble.

In water treatment, calcite is primarily used for pH adjustment and neutralization. Here’s how calcite functions in water treatment:

  1. pH Adjustment: Calcite is known for its ability to raise the pH of acidic water. Water with low pH (acidic water) can be corrosive and may lead to damage to plumbing systems and appliances. By adding calcite to such water, the mineral reacts with the acidity, increasing the pH and bringing the water to a more neutral state.
  2. Neutralization of Acids: Calcite acts as a buffering agent, neutralizing acids in water. When acidic substances are introduced into water, calcite helps mitigate the acidic nature by reacting with the acids and reducing their impact.
  3. Corrosion Control: The use of calcite in water treatment is essential for corrosion control. Acidic water has the potential to corrode pipes and plumbing fixtures. Calcite helps neutralize the acidity, reducing the corrosive effects on metal surfaces and preventing damage to the water distribution system.
  4. Enhancement of Water Quality: Beyond pH adjustment, calcite can contribute to the enhancement of water quality by improving taste and clarity. It aids in the removal of metallic tastes associated with acidic water, resulting in water that is not only neutral but also more palatable.
  5. Environmental Considerations: Calcite is a natural and environmentally friendly substance, making it a preferred choice for water treatment systems that prioritize sustainability and eco-friendliness.

In water treatment processes, calcite is often incorporated into filtration systems or contactors where water passes through a bed of calcite media. The interaction between the water and calcite particles facilitates the desired pH adjustment and neutralization.

Overall, calcite’s role in water treatment is fundamental for achieving balanced pH levels, preventing corrosion, and enhancing the overall quality of water for various applications, including residential, industrial, and municipal purposes.

Calcite is a naturally occurring calcium carbonate media. One of the advantages of Calcite is its self-limiting property. When properly applied, it corrects pH only enough to reach a non-corrosive equilibrium. It does not overcorrect under normal conditions. Upon contact with Calcite, acidic waters slowly dissolve the calcium carbonate to raise the pH which reduces the potential leaching of copper, lead and other metals found in typical plumbing systems. Periodic backwashing will prevent packing, reclassify the bed and maintain high service rates. Depending on pH, water chemistry and service flow, the Calcite bed will have to be periodically replenished as the Calcite is depleted.

As the Calcite’s calcium carbonate neutralizes the water, it will increase hardness and a softener may become necessary after the neutralizing filter.

Calcite can be effectively combined with Clack Corosex to combine the high flow neutralization properties of Corosex, along with the slower reacting low flow properties of Calcite, increasing the ability to correct low pH.


Naturally occurring material
Low uniformity coefficient for maximum contact for controlled pH correction
Slower, reacting for controlled pH correction


Color: Near white
Bulk Density: 90 lbs./cu. ft.
Mesh Size: 16 x 40
Specific Gravity: 2.7
Effective Size: 0.4 mm
Uniform Coefficient: 1.5
Hardness: 3.0 (Mohs scale)
Composition: CaCO3′ 95% min.
MgC03′ 3.0% max.


A gravel support bed is recommended
Water pH range: 5.0-7.0
Bed depth: 24-30 in.
Freeboard: 50% of bed depth (min.)
Backwash rate: 8-12 gpm/sq. ft.
Backwash Bed Expansion: 35% of bed depth
Service flow rate: 3-6 gpm/sq. ft. but may be modified to adapt to local conditions

Service Flow Pressure Drop and Backwash Bed Expansion charts to be added later. Check back for updates.


Part No. A8021-01
Description: Calcite
Cu.Ft./Bag: .55 (50 lbs.)
Wt./Cu.Ft.*: 90 lbs.
Bags/Pallet: 49
Weight/Pallet: 2486 lbs.
Pallet Dim. 48″x40″x32″

Tested and listed under ANSI/NSF Standard 61 for Health Effects.