Mineraluxe Calcium Plus is a highly refined, calcium-rich mineral designed to raise hardness levels in hot tub water. A clean, white prill, this product is used when calcium levels are low to raise them up. This prevents premature deterioration of tub surfaces including synthetics and vinyl and unnecessary corrosion of equipment and metal surfaces. Calcium Hardness also plays an important role in ensuring the overall mineral balance is correct, enhancing comfort, chemical efficiency and cost of maintenance.