Why is Pool pH Important?

Keeping your pool pH in the correct range is a vital component of keeping your pool safe and sanitary. If the pH is outside of the range of 7.0 to 7.6, the chlorine cannot sanitize the water properly and kill any algae growth. Below are a few other effects of high or low pH levels.

High pH

  • Calcium in the water combines with carbonates to form scales at the edges of the pool, trapping dust and dirt and eventually turning black.
  • Water becomes cloudy.
  • Calcium carbonate clogs the sand in the filter, and the sand becomes similar to concrete. It then destroys the effectiveness of the filter.
  • You need 80 percent more chlorine to do the same work because the chemical isn't as effective.
  • Eyes and nose burn. Skin gets dry and itchy.

Low pH

  • The water begins to dissolve the surface of the grout, plaster, or other material that makes up the bottom and walls of the pool. The surfaces become rough and make a good home for algae.
  • Metal corrodes, including ladders and rails in the pool and pipes and fittings in the filter.
  • As the metal corrodes, sulfates form, which attack the walls of the pool and form brown or black stains.
  • Chlorine activates and evaporates too fast to sanitize the water.
  • Eyes and nose burn. Skin gets dry and itchy.
  • Swimwear and pool toys fade, and the water damages other materials.  

For optimal swimmer comfort as well as chlorine effectiveness, aim for a pH between 7.2 and 7.4. This is the natural range of pH for your eyes.