Signs of High pH in Pool

Pool pH will always fluctuate constantly, especially when you are dealing with so many variables as in a swimming pool. When it moves you will most likely find the pH of your pool drops to acid levels, especially in late summer when the load or usage is higher than the start of the season. But there will be times when the pH climbs on the scale and there will be signs of it. What are the signs of high pH in a pool?

Once the pH moves too high 7.8+ you’ll hear complaints about irritated skin, stinging eyes, dry skin, & sticky feelings from swimmers. You’ll notice that the H2O has become hazy/cloudy losing its appeal to those who use the pool, finally, test the pH of the pool H2O for a higher-than-normal result.

It will be a long summer if the reagents aren’t new and past their shelf life or you aren’t running the basic test you need to operate a swimming pool. Either way, Get on the Ball! or it will be a long hot summer.

Signs of High pH in Pool


pH measures the activity of free hydrogen and hydroxyl ions within a solution. While this is harder to figure out for the average person, that is why chemical testing strips have been created for the everyday pool owner. pH is testing the alkalinity and acidity in your swimming pool. Having your pH levels properly balanced ensures that the chemicals in your pool are at their optimum working range.

If your pool’s pH reading is too high there are more signs that you will start to notice. Irritated skin is a sign of a high pH level. Also, if you have too high of a pH level, it will start to affect the way chlorine cleans your swimming pool. You will start to notice it is not as clean as it once was.

If your swimming pool becomes cloudy this is a sure sign that the pH level in your swimming pool is too high. You need to address it right away. If your pH is not in the ideal range then your chlorine won’t protect the pool water from organic contaminants like algae that will slowly wait in the cracks and crevices of your pool for the chlorine residual to deplete and then they will spring into action populating your pool until it looks emerald green and in no time at all.


  • Proper pool pH is right in the middle of the spectrum the pH should be between 7.3 and 7.6 for optimum performance and the cleanest water. If you are testing regularly you should have seen some hints like the TA or total alkalinity starts to slide out of the ideal range of 80-120 ppm.
  • Alkalinity is the capacity of pool water to resist acidification. It should not be confused with which is a measurement on the pH scale.
  • Always remember pH is always after the fact.
  • If the pH gets higher than 7.8, the water is becoming too alkaline.


What causes high pH in Pools?

  • Sudden rise in water temperature
  • Water features that take water out of the pool aerating it
  • Release of Carbon Dioxide(CO2)
  • Swimmers using sunblock or lotions
  • Liquid bleach, such as Clorox has a pH level of around 11-13
  • New pool surface and walls leaching in H2O
  •  Off-gassing  ………………………………………………………………………… Read more

Sources of High pH


  • Algae can raise the pH this will happen at the start of a cloudy appearance
  • Adding strong liquid chlorine, calcium, or lithium hypochlorite chlorine could raise it.
  • Suddenly heating the water, whether from a pool heater or a string of sunny days, could up the pH.
  • Saltwater pools tend to be alkaline.
  • Adding fresh water from the hose may raise it, depending on the content of your tap water.
  • For a new pool, pebble or plaster finishes can raise the pH.
  • Time raises the pH in chlorinated pools. This happens naturally.


What are the signs of Low pH in a Pool?

  • Cause Chlorine By-Products(Chloramine)
  • Impact chlorine effectiveness
  • Eye irritation
  • Cause etching of plaster, grout, stone, concrete, & tiling in concrete pools.
  • Vinyl surfaces will also become brittle, risk of cracks & tares.
  • Can result in staining & cloudy pool H2O
  • Cause Irritated skin ………………………………………………………. Read more

Lower pH in Pool


When you’ve tested and determined that your pool pH is too high, there are two ways you can adjust it:

  • Dry acid
  • Muriatic acid.

If you’re using a dry acid, use these steps:

  • Follow the manufacturer’s instructions on the package. Use the recommended dosage
  • You may be able to just add the dry acid directly or dissolve the chemical. 
  • Make sure the pool pump and filter pump are running.
  • Spread the product in the deepest part of your pool.
  • Use a pool brush to break up any clumps. This will also help disperse the dry acid evenly.

If using you’re using muriatic acid, use these steps:

  • If diluting-Never pour water into acid-pour Muriatic acid into water 
  • Read the package and follow the manufacturer’s instructions.
  • In some cases, you may need to mix and dilute the product.
  • Slowly pour the product into your pool. Take care to avoid spills and splashes where gloves and safety glasses.
  • Run the pool filter and pump unless the instructions say otherwise.
  • Apply the pH-balancing chemicals as detailed on the label.


Why is My pH Always High in My Saltwater Pool?

The reason why saltwater pools usually have elevated pH levels is that the generation of chlorine with the electrolysis process tends to create byproducts like Sodium hydroxide, also known as lye and caustic soda that have a very high pH, Sodium Hydroxide has a 13 pH and is extremely high, or .…………………………………………….. Read more


JimGalloway Author/Editor


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