SpaGuard Spa Calcium Hardness Increaser 12oz

SpaGuard's Calcium Hardness Increaser enables spa owners to increase their calcium hardness with this easy to use granular formula, which will boost your calcium hardness to above the danger zone, where low levels cause extensive corrosion of plumbing, jets, fixtures, and tub surfaces. Calcium Hardness Increaser helps raise the calcium level steadily so you don't get too much calcium and start developing scale build-up and cloudy water. The optimal calcium hardness level is 200-400 ppm, while anything below 100 ppm will cause corrosion.

Routine Maintenance:
1 tbsp per 100 gallons of water will raise hardness by 25 ppm.