GLB® Calcium Hardness Up increases water hardness to prevent foaming, equipment corrosion and scaling. 
Features:
Helps maintain proper calcium hardness level of 150-250 ppm
One pound of GLB® Calcium Hardness Increaser will increase the calcium hardness 10 ppm in 10,000 gallons of water
Applications:
Normal:
1. Determine calcium hardness level. It should be between 150-250 ppm. 
2. If the level is below 150 ppm, add CALCIUM HARDNESS UP by distributing the product over the water surface. 1 lb. of CALCIUM HARDNESS UP will increase the calcium hardness 10 ppm in 10,000 gallons of water.