Total Hardness

What It Means: Total Hardness measures the concentration of calcium and other dissolved minerals in your pool or spa water. Maintaining the right level is critical for both the comfort of swimmers and the longevity of your pool equipment. Water that is too soft (low calcium) can corrode metal components, damage plaster and grout, and reduce the effectiveness of other balancing agents. Water that is too hard, on the other hand, causes scale formation, which can clog plumbing, coat surfaces, and interfere with heaters and filters.

Ideal Range: 175–275 ppm

If Total Hardness Is Too Low: Low calcium levels mean aggressive water. This can lead to pitting of plaster, deterioration of vinyl liners, and corrosion of metal parts. To correct this, use a Calcium Hardness Increaser, available from Chlor-Dash. Follow dosage instructions based on your pool's volume, and retest after circulation.

If Total Hardness Is Too High: Excessive calcium results in scale buildup that can be difficult and expensive to remove. The most effective method of reducing high hardness is to partially drain and refill your pool with fresh, softer water. In regions with naturally hard water, you can also use a stain and scale preventative (like Metal Gone or Scale Gone from Chlor-Dash) to minimize deposits and protect your equipment.

Maintenance Tips:

• Always balance hardness before adjusting pH and alkalinity. It helps create a stable foundation.

• If you have a salt system, maintaining the correct hardness helps protect the cell and improve longevity.

Chlor-Dash Recommends:

• Calcium Hardness Increaser (for raising levels)

• Scale Gone (to prevent scale from high hardness)

• Metal Gone (to reduce staining from dissolved metals when adjusting hardness)