Stabilise pH and boost alkalinity

A safe and cost effective alternative to the use of sodium hydroxide (caustic soda) or other chemicals for wastewater alkalinity and pH adjustment.

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Has uncontrolled high pH adversely affected your treatment process ?

Trouble with your water and its alkalinity ?

Excess usage of chemical elements like lime and alum, and caustic soda leading to higher operations and maintenance cost ?


Alkalinity can be defined as the ability of a water to neutralize acid or to absorb hydrogen ions. In municipal and industrial wastewater, many factors contribute to alkalinity such as the type of dissolved inorganic and organic compounds present in the water, the amount of suspended organic matter in the water, the presence or absence of free hydroxyl alkalinity, the amount of bicarbonate in the water, or the bicarbonate to dissolved CO2 ratio etc.

The bacteria which play an active role in wastewater treatment are most effective at a neutral to slightly alkaline pH (7 to 8). Maintaining the proper pH in the wastewater as it undergoes treatment is crucial to maintaining optimal conditions for the biological activity, which is why alkalinity is so important to the wastewater industry.

ACTI-Mag to stabilise pH and boost alkalinity

ACTI-Mag has a higher neutralising value per kilo when compared with caustic whilst being significantly safer to handle than other traditional alkalis, making it a very safe and cost competitive option.

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Key Benefits

High neutralisation potential without high pH
Reduced sludge generation making for easier disposal (lower overall costs)
Solve sodium discharge issues by substituting for caustic
Safer to handle than traditional neutralisation chemicals (Lime and Caustic)

Customer Stories

Improving the Sustainability of Water Treatment \ Municipalities
Solving extreme H2S odor, El Centro

ACTI-Mag reduces the odor to manageable levels at El Centro, Southern California, United-States.

Improving the Sustainability of Water Treatment \ Municipalities
Magnesium Hydroxide liquid for odour control, Cassowary Coast Regional Council

Replace lime and alum with Calix’s ACTI-Mag magnesium hydroxide liquid at Cassowary Coast Region, QLD, Australia.

Improving the Sustainability of Water Treatment \ Municipalities
Phosphorus removal in wastewater, a UQ lab study

ACTI-Mag removes phosphate through struvite crystallization – a research study by the University of Queensland.


When an alkaline compound dissolves in water it produces hydroxide ions, OH- . These ions are responsible for the alkalinity of the solution.

Because Magnesium Hydroxide Mg(OH)2 provides two hydroxides for alkalinity compared to one with NaOH caustic soda, the usage rate for Mg(OH)2 is much less than that required for NaOH.


Neutralisation rate depends on how readily the solids dissolve to form an alkaline solution. ACTI-Mag is produced with Calix’s own highly reactive Magnesium Oxide (MgO) produced using Calix Flash calcination process. This short contact heat treatment (less than 10 sec) rapidly converts the Magnesium carbonate ore (MgCO3) to MgO by driving off CO2. As the CO2 is ‘fizzled-off’ from the fine ground mineral particles, it produces a highly porous mineral ‘honeycomb’ leaving a very high surface area. This allows for rapid hydration to MHL & the resultant high surface, reactive ACTI-Mag product is more readily released by dissolution to allow a significantly higher rate neutralisation than other low surface area, low reactivity MHL products.

ACTI-Mag lowers chemical consumption and ensures easier use, handling and storage, considerably reducing costs.


Lower cost-per-litre does not necessarily mean cheaper, it may mean lower solids concentration or low active ingredient availability due to low reactivity.
The concentration of active ingredients in Magnesium Hydroxide Mg(OH)2 impacts on the neutralisation time.

More solids (higher level of MHL per volume) = Lower required dose

At a 30% solids concentration, MHL can take more than twice the dose to achieve the same neutralisation capacity as the amount of ACTI-Mag, which would result in significantly higher annual consumption costs.

Relevant articles

November 22, 2019 \ Improving the Sustainability of Water Treatment
Calix is a proud corporate partner of WaterAid

Calix is a a proud corporate partner of WaterAid Calix has become a corporate member of WaterAid, an international not-for-profit

November 22, 2019 \ Improving the Sustainability of Water Treatment
New acquisition of Inland Environmental Resources to accelerate US market

Calix looking to accelerate US market entry through the acquisition of Inland Environmental Resources. Inland Environmental Resources, Inc. (IER) is

September 02, 2019 \ Improving the Sustainability of Water Treatment
Solving extreme hydrogen sulphide and odour issues in Southern California

El Centro, a city 100 miles east of San Diego, was experiencing significant issues with odour control in its sewer

The Calix difference

People, unique technology, partners, and track record

  • Calix Technology

Faster reactivity = less costs

Calix core technology makes high surface area materials (with a honeycomb-like structure), giving you a price and a reactivity advantage.

Our materials are proving to have similar properties to highly active nano-materials, without the health/safety concerns and high cost, but with all the benefits.

To learn more about how Calix technology works, click here.

  • Calix supply chain

Calix is able to offer better service, reliability and performance to its customers because it controls the entire production process from mining of raw materials, processing and production.

Calix owns and operates a mine, production, testing facilities and close-to-customers manufacturing plants.

From mine to customer!

  • Continuous Improvement

Calix is committed to providing process development, manufacture, delivery and application of mineral based
products and services that meet the needs of our customers.

We aim to ensure that quality is everyone’s aim throughout the organisation and that each employee has a sound understanding of the importance of our quality management system and their direct effect to our continuous success.

Our AS/NZS ISO 9001 certified quality system and safety, health and environmental management system are vital elements of our engineering and quality services.

  • A culture of innovation

Calix leverages a culture of innovation to provide fully customised services such as design expertise, engineering know-how, detail engineering, installation, piping and commissioning services to provide turnkey systems for chemical dosing of Magnesium Hydroxide Liquid (MHL).

Our engineered and cost-effective solutions are tailored to meet your specific needs and budget. Quick to install – our modular dosing units can be delivered on site by truck and are fast to set up and connect.

To find out more about our dosing solutions, click here.

Calix has its own direct delivery, service and support capabilities and also has an established a network of local distributors and partners that can provide the best solution for your specific needs and ensure you receive excellent customer service and support, wherever you are located.

Contact Us

Calix is committed to providing a high level of customer service. Whether you are looking for information relating to our solutions, have a comment, are looking for a new career, or want information on our performance, use the form below to get started.

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