pH Correction Filters for Acidic & Corrosive Water

Low-pH water can be corrosive to pipes, fittings, pumps, geysers and appliances. H2O Warehouse supplies complete Calcite pH-correction vessels and replacement media for residential, commercial, borehole and wellpoint applications.

These systems work by passing acidic water through calcium-carbonate media, which gradually dissolves and raises the pH. Correct sizing is important because performance depends on the starting pH, alkalinity, acidity, flow rate and contact time.

Shop pH Correction Filters

Browse complete Calcite vessels from compact residential sizes through to higher-flow commercial systems.

View Complete pH Correction Vessels

Choose Your pH Correction Option

Complete Calcite Vessels

Ready-to-use FRP vessels supplied with Calcite media and the required filtration head. Available in multiple sizes for residential, commercial and higher-flow applications.

Shop Complete Vessels

Replacement Calcite Media

Replacement and top-up media for existing pH-correction vessels. Calcite is gradually consumed during treatment and must be checked and replenished periodically.

Shop Replacement Media

Available Complete Vessel Sizes

Vessel	Typical Use	View
10×35	Compact residential and lower-flow applications	View
10×54	Small whole-house and light commercial use	View
12×52	Residential and moderate-flow whole-house systems	View
13×54	Larger homes and light commercial applications	View
14×65	Higher-capacity residential and commercial use	View
16×65	Commercial and higher-flow installations	View
18×65	Larger commercial treatment systems	View
24×72	High-flow commercial and industrial applications	View

What Problems Can Low-pH Water Cause?

Pipe & Fitting Corrosion

Acidic water can attack copper, galvanised steel, brass and other metallic components, increasing the risk of pinhole leaks and premature failure.

Blue-Green or Rust Staining

Corrosion may release copper or iron into the water, causing coloured staining on sanitaryware, basins and fixtures.

Metallic Taste

Low-pH water can dissolve metals from plumbing and create an unpleasant metallic taste or odour.

Equipment Damage

Pumps, geysers, valves, heat exchangers and treatment equipment can suffer accelerated wear when corrosive water is left untreated.

How Calcite pH Correction Works

As acidic water passes through the vessel, a controlled portion of the Calcite media dissolves. This adds calcium carbonate, raises pH and increases alkalinity, helping reduce the water’s corrosive tendency.

Calcite is consumed over time and requires periodic top-up.
The vessel must be sized for the required service flow and contact time.
Backwashing or periodic media agitation may be required depending on the vessel head and water quality.
Very low pH or high acidity may require a blended media or chemical dosing solution rather than Calcite alone.

Important: pH Correction Is Not Water Softening

Calcite raises pH by adding calcium carbonate to the water and may increase hardness. Where hardness or scale is also a concern, the pH-correction vessel may need to be followed by a correctly sized water softener or another suitable scale-control stage.

Recommended Installation Sequence

A typical borehole-water arrangement may be:

Pre-filtration → Iron/Manganese Treatment if Required → Calcite pH Correction → Additional Polishing → UV Disinfection → Final Safety Filter

The correct sequence changes with the water analysis. For example, pH may need correction before certain iron-removal media, while other applications may require oxidation or sediment removal first.

Information Required Before Selection

Raw-water pH
Total alkalinity and, where available, acidity
Total hardness reported as mg/L CaCO₃
TDS or conductivity
Iron, manganese and turbidity
Water source and intended use
Required service flow in m³/h
Daily or monthly consumption
Pipe size, available pressure and installation space

Replacement Media

Calcite pH Fix Media – 25 kg

Replacement calcium-carbonate media for refilling or topping up compatible pH-correction vessels.

View Calcite Media

Need Help Sizing a pH Correction Vessel?

Send us your complete water analysis, expected flow rate, water consumption and installation details. We can recommend the correct vessel size, media quantity and treatment sequence.

Request Technical Assistance

Important: pH alone is not sufficient for reliable system selection. Final sizing must consider alkalinity, acidity, carbon dioxide, hardness, flow rate, contact time and the full water-treatment process. Post-treatment testing is recommended to confirm the achieved pH and stability.