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How to decrease Total Alkalinity

  • Updated

My total alkalinity is high, what should I do?

There is a method for lowering the total alkalinity. But remember that the pH and alkalinity are tied together. 

First, determine if there is an issue:

  • Is the water cloudy or dull-looking?
  • Did you calculate your CSI (calcium saturation index) and determine you need to lower the total alkalinity?
  • Are you constantly battling the pH rising?

These are all the issues related to high alkalinity. If you do not have any of these issues, it is likely perfectly fine for your alkalinity to be on the higher side. Every reading doesn't have to be perfect for a good swim or soak.

Second, decide on how to solve the issue:

  • DIY fast: do you want to learn how and take full control of your pool as fast as possible? We do not recommend allowing swimmers in the pool until the pH has returned to normal.
  • DIY relaxed: do you have no major issues, but you want to go in the right direction? During this method, it is okay to allow swimming when you normally would.

DIY fast

  1. Locate the return jets for your pool or spa. Water features such as waterfalls or fountains also work well. Return jets should be pointed upward so that the water surface is broken while the pump is running.
    Running water features or returns to break the water surface helps add air to the pool. This is what will be removing the alkalinity from the pool.
  2. Lower the pH to 6.5-6.8. This will depend on your test kit, the Sutro Monitor will read the pH down to at least 6.8.
     Run the pool pump and water features normally, or for extra time to speed up the process.
  3. The pH will slowly rise as the water is aerated.
  4. Continue to monitor the pH and total alkalinity, if the pH goes above 7.0 and the total alkalinity still needs to be decreased by over 100 ppm, lower the pH back down to 6.5-6.8.
  5. Once the desired total alkalinity is reached, re-adjust the pH to 7.4-7.6. Adjusting the pH up will increase the alkalinity slightly, but not put it out of range again.

DIY relaxed

This is a similar process to the "fast" version. However, the pH is not lowered as drastically. This should take approximately 10 times slower but you can maintain a more neutral pH.

  1. Locate the return jets for your pool or spa. Water features such as waterfalls or fountains also work well. Return jets should be pointed upward so that the water surface is broken while the pump is running.
    Running water features or returns to break the water surface helps add air to the pool. This is what will be removing the alkalinity from the pool.
  2. Lower the pH to 6.8-7.0. This will depend on your test kit, the Sutro Monitor will read the pH down to at least 6.8.
     Run the pool pump and water features normally, or for extra time to speed up the process.
  3. The pH will slowly rise as the water is aerated.
  4. Continue to monitor the pH and total alkalinity, if the pH goes above 7.0 and the total alkalinity still needs to be decreased by over 100 ppm, lower the pH back down to 6.8-7.0.
  5. Once the desired total alkalinity is reached, re-adjust the pH to 7.4-7.6. Adjusting the pH up will increase the alkalinity slightly, but not put it out of range again.

Need help?

Please reach out to customer support if you need help with this process.

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