Alkalinity

This usually comes in granular form. The Alkalinity acts as a stabiliser for the PH. If it is not at the correct level, which should be between 80 – 100, then the PH will be susceptible to irregular readings. 

To raise the alkalinity, sodium bicarbonate (alkalinity increaser) is used. As always pre-dissolve the chemical in a bucket of pool water before adding to the swimming pool. To raise the TA by 10 mg/L, dose 180 g per 10 m³ into a separate bucket, and add the solution directly into the pool water.

To lower the alkalinity either use Hydrochloric acid, which is liquid form, or Sodium Bisulfate, which is granular.

When using hydrochloric acid, it needs to be poured directly into one place in the deep end of the swimming pool, for dosing rates follow the chart below:

Water Volume

In Litres

Water Volume

In Gallons

Reducing

By 10ppm

Reducing By

25ppm

4,545 1,000 100ml 250ml
9,090 2,000 250ml 625ml
22,700 5,000 500ml 1.25ltr
45,450 10,000 1.00ltr 2.5ltr
68,175 15,000 1.5ltr 3.75ltr

 

When using Sodium Bisulfate, it needs to be pre-dissolved in a bucket of pool water first then, as with hydrochloric acid, poured into one place in the deep end of the swimming pool, for dosing rates follow the chart below:

Water Volume

In Litres

Water Volume

In Gallons

Reducing By

10ppm

Reducing By

20ppm

4,545 1,000 71g 142g
9,090 2,000 145g 283g
22,700 5,000 363g 709g
45,450 10,000 709g 1445g
68,175 15,000 1077g 2183g

 

Note: Dosing rates may vary depending on the manufacturer/brand, always read the label before applying chemicals to swimming pool water.