pHminus, or pHdown, is the name given in the pool industry for a chemical known as sodium bisulphate or sodium bisulfate.

It is mainly used to reduce the pH in swimming pool water, but it does have some other uses, especially in the food industry.

It is a dry powder or granulated chemical used instead of dangerous hydrochloric or muriatic acid.

Although it should be used with caution, ideally wearing rubber gloves and a face mask, it does not give off any fumes, and is safe to store in a pump room. It should be dissolved in water before adding to the pool.

Our sodium  bisulphate is a very high quality, manufactured in Germany. We offer it for sale in quantities of 5Kg, 20,KG, and 50Kg.

T reduce the Ph by 0.1 add 100g per 10m³ 

See our pH minus HERE.

What is 'pH'?
In chemistry, pH is a scale used to specify how acidic or basic a water-based solution is. Acidic solutions have a lower pH, while basic solutions have a higher pH. At room temperature, pure water is neither acidic nor basic and has a pH of 7.

At 25 °C, solutions with a pH less than 7 are acidic and solutions with a pH greater than 7 are basic (alkaline). The neutral value of the pH depends on the temperature, being lower than 7 if the temperature increases. The pH value can be less than 0 for very strong acids, or greater than 14 for very strong bases.

The pH scale is traceable to a set of standard solutions whose pH is established by international agreement. The pH of water  can be measured with a glass electrode as used in digital pH testers, or a color-changing indicator such as paper test strips or colour-changing liquid in test tubes.

Measurements of pH are important in swimming pools because if the pH level is wrong, the chlorine tablets or other disinfectants will not work.

The pH of swimming pool water must be kept between 7.2 and 7.6

Disinfection systems such as  ionisers, salt water chlorinators, or UV, provide their best results at pH levels of 7.2 to 7.3.

Don't hesitate to contact us for advice before buying