Water Chemistry Problems: Calcium Hardness

PROBLEM:  High calcium hardness (above 400 ppm)

POSSIBLE CAUSES:  Naturally hard water, corrosion of plaster surfaces, use of products containing calcium hypochlorite or addition of too much calcium hardness increaser.

SOLUTION:  High levels of calcium hardness can lead to cloudy water and scale formation, especially in the presence of high pH and total alkalinity. Levels up to 400 ppm are usually not a problem, if normal chemistry is maintained. Levels over 400 ppm can be controlled by the addition SUN® Scale & Metal Control II or the replacement of some of the water with softer water. To prevent further increases in the calcium hardness levels, do not use products containing calcium hypochlorite for sanitizing or shocking purposes.

PROBLEM:  Low calcium hardness (below 200 ppm)

POSSIBLE CAUSES:  Naturally soft water or failure to add calcium hardness increaser.

SOLUTION:  Low levels of calcium hardness can lead to the corrosion of plaster surfaces, especially in the presence of low pH and total alkalinity. Plaster pools should be increased to 200-225 ppm and vinyl and fiberglass pools raised to 175-225 ppm. SUN Pool Hardness Treatment can be used to boost the calcium hardness to the proper level.