This way you can see much better when the granules have dissolved fully. To increase Chlorine levels by 1ppm add 2g of granules per 1000 litres of water (e.g 14g for 7000 litres of water). Optimum levels of chlorine for Pools is between 1 and 3ppm (parts per million) and between 3 and 5ppm for spas and hot tubs.
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