pH Correction Agents

Correct pH balance is a key factor in many processes. pH plays a significant role in everyday life from blood composition in the human body, to plant growth, to the application of paint. Many water treatment processes like chlorination, chloramine formation, and floc formation during coagulation are heavily dependent on water pH.

Moreover, pH influences corrosion and the efficiency of iron and manganese removal.

pH correction must be the first step in any water treatment sequence because it will influence further chemical reactions. We can help verify pH levels in raw and treated water.

The Avalon Institute's water quality assessment services can determine the type and quantity of pH correction agents required.

pH correction agents are available through the Osorno Store in 1 litre bottles, 20 litre delcans or 208 litre drums.

Sodium Hydroxide / Sodium Carbonate

Sodium hydroxide and sodium carbonate (soda ash) are effective pH correctors.  However, we only recommend using soda ash to increase water alkalinity.

Some uses of sodium hydroxide include:

1. Manganese can be removed only after adding an oxidant and at a pH of 7.8 – 7.9.
2. Iron removal also requires adding an oxidant and a pH of 7.4 – 7.9.
3. Formation of floc in flocculation/coagulation is pH dependent, and each flocculant has its own flocculation pH.
4. Corrosion processes speed up if the pH in water reservoirs and distribution lines is lower than 7.8.

We suggest using sodium hydroxide instead of soda ash when you want to increase pH.  Sodium hydroxide is twice as effective at increasing pH than soda ash. For a given pH correction, the sodium content will increase only by half, which is more important for people concerned with sodium in food and water.

Sodium Hydroxide 20% (Caustic Soda, ANSI60 certified), Sodium Hydroxide Pellets, and Sodium Hydrogen Carbonate (Soda Ash) can be purchased from the Osorno Store.

Download our pH Correction brochure

Download label for Sodium Hydroxide 20%

Hydrochloric Acid

We recommend using hydrochloric acid to decrease pH for swimming pools and water treatment plants.  

For swimming pools:

• The pH level in swimming pools must consistently be within a range of 7.4 – 7.6 to avoid irritation.
• Chlorination is more effective when the water's pH is below 7.4.
• Too high of a pH can lead to a hazy, murky, or cloudy pool.
• Over time, high pH can cause water to scale, resulting in clogged filters and fittings.

For water treatment plants:

• Manganese removal requires adding an oxidant and a pH of 7.8 – 7.9.
• Iron removal requires a pH of 7.4 – 7.9.
• Coagulation processes depend on the coagulation agent, but usually a pH below 6.

You can purchase Hydrochloric Acid 9% (ANSI60 certified) and Hydrochloric Acid 20BE (ANSI60 certified) from the Osorno Store.

Download our brochure

Download label for hydrochloric acid