What is Overstabilization?

Overstabilization is the buildup of cyanuric acid in swimming pool water resulting from the use of stabilized sanitizers and stabilized shock products. It significantly decreases the effectiveness of chlorine in killing germs, bacteria and algae. While small levels of cyanuric acid do serve a purpose in protecting chlorine from sunlight degradation, too much will negate any benefit and cause problems.

HTH® and calcium hypochlorite (cal hypo) offer the only complete solution to overstabilization. Cal hypo products do not contain cyanuric acid and will not cause overstabilization.

What are the Symptoms of Overstabilization?

• Cloudy water

• High chlorine reading with algae

• Adding chlorine does not get rid of algae

What is the Solution to Overstabilization?

1. Turn on the pool pump and make sure it does not need to be backwashed or cleaned and make sure it is running properly.

2. Test and adjust the stabilizer level to 25 - 50 ppm by partially draining some water from the pool and top-off with fresh water.

3. Adjust the total alkalinity to 80 - 120 ppm, the pH to 7.2 - 7.8, and the chlorine to 1.0 - 3.0 ppm.

4. Continue with routine pool maintenance program.

Note: Adjust dosages to fit your pool capacity. Ensure pH and chlorine levels are within the correct range before swimming.

Contact an HTH Pool and Spa Care Specialist for more information on overstabilization.

Recommended Products

HTH® pH Plus® Use this product to raise pH levels.

HTH® pH Minus Use this product to help lower pH levels.

HTH® Alkalinity Plus Use to maintain proper pH level or raise alkalinity in pool water.