pH Level Testing - How pH level Relates to Swimming Pool Water Chemistry!

pH level testing along with the disinfection testing of your swimming pool, are two of the most important tests that you have to do on your pool water. The reason for this is that you have to maintain a proper water balance that will ensure the safety of your bathers and swimmers.

These two tests are carried out several times a day according to pool health code standards.

The frequency at which you perform these two tests, is very important. Because the chlorine disinfection and pH levels are the two balancing factors that change the most.

Factors that can affect pool disinfectants and pH levels!

Your swimming pool water chemistry can be affected by several factors which include:

  • Your bather loads.
  • The sunlight.
  • The rainfall.

Your pH level testing should always be conducted before opening any of your water facilities. This will ensure that the conditions of your water facility is safe for swimmers to use at all times. It is also very important that you carry out a pH level testing on your pool or spa water at its highest bather and environmental load conditions.

By doing this, you will ensure that your swimming pool disinfectant system, is keeping up with the bather load demand.

pH level testing in your swimming pool or spa

When it comes to pH level testing, the procedure is a fairly straight forward one. A solution called Phenol red is used during the test of your pool water sample.

There are a couple interfering factors that you have to be aware of though.

These factors can result in the wrong reading doing your pH level testing. They include:

  • High chlorine levels. If your chlorine chemistry levels are too low, it can cause your pH test to come out wrong.

    Once your free available chlorine is above 5.0 ppm, you will need to neutralize it. You can achieve this by adding one drop of a chlorine neutralizer...marked R-0007 in your Taylor test kit into your water sample. This is done before you add your pH indicator.

  • High bromine ion. If you have a high level of bromine ions in your swimming pool, again your pH test can be affected. Providing your pool or spa is on a bromine system or if you have used a bromine salt (algaecide), it may cause your phenol red to turn bromthyol blue.

    This could result in a purplish color during your pH level testing. This type of reading occurs even if your pH is low.

Understanding the pH level testing scale!

The table below should be used when you are conducting a test of the pH in your swimming pool. This table will help you determine which type of action is needed to correct your pH level. You may have to adjust your pool pH with either acid or baking soda (sodium bicarbonate), according to your results.

Corrosive WaterBalance Pool WaterScale Forming Environment
6.6 to 7.07.2 to 7.87.9 to 8.4

What to do after your pH level testing?

What you should do when the pH level of your pool water is too high? Apart from checking your pH levels, there are times when you may have to increase or lower your pH levels. In order for you to correctly adjust the pH levels in your swimming pools and spas, you need to conduct an acid demand and a base demand test.

This is an extremely important procedure - which is designed to help you make the correct adjustment to the pH level of your pool water. Once you have done your pH test, you will keep the water sample. At this point, you will add either a base or acid demand solution to determine the amount of acid or soda ash you will need for your adjustment.

The number of drops that it took to reached the desired color is recorded. Upon your results, you will refer to your chemical dosing chart which will tell how much soda ash you have to add.

Meanwhile, if there is a need for you to decrease the pH level of your pool water, then you will add the acid demand solution instead. Once more, this procedure is done drop-by-drop, until the desired color is achieved.

Once completed, record the number of drops that it took to reach the desired color change. Now once again you will refer to your chemical dosing chart.

The chart will indicate how much acid you need to add to your pool water, to safely adjust your pH level. Special note: One very important point that you should always remember here. And that is this! Your pH level is the single most important element in your swimming pool water chemistry.

It has to be at industry standard at all times. Why? Because it affects every other pool chemical balance in your pool or spa water. For this reason, you have to maintain your swimming pool water chemistry through daily pH level testing.

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pH level testing ensures your swimming pool safety!

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