Stable total alkalinity helps to maintain the pH level of water.
Instructions for use: Maintain total alkalinity in the range 100-160 mg/l (ppm).
Add 27 grams of alkalinity plus per 1500 litres of water to increase the total alkalinity by 10mg/l (pmm).
Mix in a bucket of water and pour into spa. (One level capful is approx 20g).