How to Lower the Total Dissolved Solids (TDS ) in Your Pool Water

Updated February 21, 2017

Swimming pool water is kept clean and clear partially through good water chemistry, which is negatively affected by high levels of total dissolved solids (TDS). The most common components of TDS are calcium and sodium compounds, reports "The Pumproom Press." Over time, a pool's TDS are increased by the periodic addition of chemicals and even water. Unfortunately, there's no chemical you can add to a swimming pool to reduce high TDS levels. Instead, you'll need to partially drain your pool and refill it with fresh water.

Consult your local municipal codes before emptying your swimming pool of any water. Many areas have restrictions on emptying chlorinated or salty water.

Rent or buy a submersible sump pump strong enough to pump out pool water and an accompanying hose long enough to extend to a sewer access point.

Lower the submersible sump pump and its hose to the bottom of the deep end of your swimming pool. Plug the sump into an electrical socket and start it up so it begins pumping out water.

Drain your swimming pool down to about the halfway point. To prevent damage to exposed pool surfaces, spray the walls of the pool every time the water level drops about 12 inches.

Stop and unplug the submersed sump pump once your pool has been drained to the halfway point. Remove the sump pump from the bottom of your swimming pool and the hose from the sewer access point.

Hook up a garden hose and refill your partially drained swimming pool with fresh water. Spray the walls to keep them moist as you're refilling.


Skip renting sump pump equipment and hoses if you have a pool pump and a main drain that allows you to just drain the pool that way. Test your refilled pool for proper chemical levels, shock it, then adjust chemical levels as needed.


If you drain your pool too much, problems such as heaving or buckling could occur. Always consult a certified pool professional, if you need to fully drain your pool, recommends the website Pool Solutions.

Things You'll Need

  • Submersible sump pump and hose
  • Garden hose
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About the Author

Tony Guerra served more than 20 years in the U.S. Navy. He also spent seven years as an airline operations manager. Guerra is a former realtor, real-estate salesperson, associate broker and real-estate education instructor. He holds a master's degree in management and a bachelor's degree in interdisciplinary studies.