The active material selected for the pH minus liquid product is sulphuric acid at a 50% concentration.
In a swimming pool, it is preferable to use this product rather than hydrochloric acid for several reasons:
- In water, hydrochloric acid generates chlorines. These destabilise the water balance and increase corrosion. In drinking water, it is preferable to keep this rate lower than 250 mg/l.
- At an identical concentration, sulphuric acid is more acidic than hydrochloric acid.
- Acti pH minus liquid has a 50 % sulphuric acid content, whereas hydrochloric acid is sold with a 33 % level of active material.
- The hydrochloric acid marketed at 33% by mass emits fumes, whereas the pH minus product does not.
These fumes are harmful to users, making it mandatory to wear an isolating independent breathing mask when using 33% strength hydrochloric acid.
These fumes are also highly corrosive and will corrode the electrical equipment housed in the technical facility. This means you would have to store and use drums of hydrochloric acid outdoors, well away from any electrical equipment.
To sum up, Acti pH minus liquid is more efficient than hydrochloric acid for the purpose of pH rectification, it does not generate any nuisances in the swimming pool, and it is less hazardous to use.