How-To Guides | pH & Alkalinity Problem Solving

This section is for those with unusual pH and/or Total Alkalinity relationships, and have trouble getting them into balance. If you're new to spa water chemistry, read the ABCs of Water Chemistry and Hot Tub Prep & Maintenance, first.

99% of spa owners will have no difficulty getting their water into proper balance. But like hot tub users themselves, there's great diversity in water types from region to region, even within communities. Municipal water supplies differ from well water. This sometimes leads to difficulty in getting pH and Total Alkalinity (TA) into balance.

We have good products available to us to correct most spa water chemistry problems. Remember, we can't always get the water chemistry perfect. That said, it's better to have pH & TA readings on the high side than readings which are too low. Do the best you can, but don't lose any sleep if you can't get your readings perfect.

Problem: pH and TA are both very low

Add Alkalinity & pH Up to gently raise both pH and TA.

Problem: pH and TA are both high

Add Alkalinity & pH Down to lower high TA or pH.

Problem: pH or TA are stubbornly high

Add Acid Magic to lower very high TA or pH.

Problem: pH is normal, but TA is high

Add Alkalinity & pH Down to lower TA. Circulate water with pump on high and blower activated to aerate water for half an hour and retest.

Problem: pH is normal, but TA is low

Add Alkalinity & pH Up to raise TA.

Problem: pH is high, but TA is normal

Add Alkalinity & pH Down to lower pH. If TA drops below normal range, circulate water with pump on high and blower activated to aerate water for half an hour and retest. Add Alkalinity & pH Up to bring it back up.

Problem: pH is high, but TA is low

Add Alkalinity & pH Down to lower pH. Circulate water with pump on high and blower activated to aerate water for half an hour and retest. Then add Alkalinity & pH Up to bring TA back into range. It will not raise pH above normal range.

Problem: pH fluctuates wildly

This is usually caused by low TA. Bring TA into line with Alkalinity & pH Up as needed, making final adjustments to pH if necessary per this guide. You can help lock pH into range with pH Perfect Balance after adjustment.

Problem: pH drops after adding non-chlorine shock

Prevent this by adding about 3/4 teaspoon Alkalinity & pH Up per tablespoon of non-chlorine shock used.

Problem: Bad source water or well water makes balancing difficult

Reduce contaminants by using a hose-end water filling filter PreFresh Spa Fill Filter

Tips

  • IMPORTANT: After adding chemicals, allow your water to circulate before retesting, especially if you have problems balancing. Wait for a few hours, or retest the next day for accurate readings.
  • Total Alkalinity should be kept between 80-120 ppm.
  • pH range is ideal between 7.2 and 7.6. Too low is acidic and will cause corrosion. Too high can result in scale formation.
  • For best results, place water sample into a clean cup and test it after it has cooled a few minutes.
  • Never mix different chemicals together prior to addition to the spa water. Add them one at a time. Pre-dissolving granules in a plastic bucket of water is best.
  • Make sure your water hardness is not too low. Adjust it prior to making final pH and TA adjustments. A good range for calcium hardness is 150-300 ppm.
  • Check Total Alkalinity (TA) first, then adjust for proper pH range. Proper TA will buffer pH, that is, it will help to prevent pH fluctuations.
  • Use fresh, high quality test strips.
  • Excessively high bromine or chlorine levels can result in false pH and TA readings.
  • Change your spa water at least every 3 to 4 months, depending on bather load.

Technical Information

Alkalinity & pH Up is sodium bicarbonate (also called sodium hydrogen carbonate). It raises Total Alkalinity, and pH which is too low.

Since it has a pH of only 8.3, it will generally have a lesser effect on pH. Diluted in water, Alkalinity Increaser will not raise pH above its normal range. Proper TA will buffer pH, and help prevent pH fluctuations.

Alkalinity & pH Down is sodium bisulfate. It reduces Total Alkalinity and pH which is too high.

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