High pH High Alkalinity

There are way too many explanations on the internet when it comes to the chemical balance of your swimming pool but the easiest way to explain it is most good and bad things that happen in your pool are a response to pH moving in either direction upsetting that balance. How do you adjust High pH with High Alkalinity?

  • Run pool pump-bypass filter
  • Test Total Alkalinity
  • Calculate Muriatic Acid addition with a Pool Alkalinity Calculator
  • Mix Muriatic Acid in a bucket of pool H2O
  • Evenly distribute by walking around the perimeter of the pool
  • Wait 6-8 hrs
  • If TA is 80-130 ppm
  • Adjust pH with pH increase/aerate to naturally raise


Once the Total Alkalinity (TA) is in check the pH and Chlorine will fall in line because Alkalinity is the muscle in your swimming pool’s water chemistry and is able to offset bad changes from happening too quickly for you to respond. It is the most important pool test you can run.


High pH High Alkalinity


Lower pH makes your swimming pool water acidic. If you let your pool pH get too low, several health and maintenance issues will develop. Your pool experience deterioration in your tiling, plaster, stone, grout, and concrete.  This will cause etching of vinyl surfaces which will increase its tears and cracks.  It will affect the filter’s efficiency. It can also lead to health issues for swimmers.

Maintaining an optimal pH is important because it can impact the effectiveness and efficiency of the chlorine, which ultimately will lead to unsanitary swimming conditions. The elevated alkalinity may cause your pH level to rise along with it. This affects the pool water and its water chemistry and may lower chlorine residual.

Chlorine efficiency is dependent on pH, which can raise it too high or lower it on recommended results on a scale of 0 to 14, with 7.0 being neutral and desirable for chlorine kill.



Effects of High Alkalinity and High pH in Pool Water



When high alkalinity levels increase in pool water for whatever reason, they will naturally decrease over time on their own. But high total alkalinity levels can increase the chance of other issues, like high pH and ineffective chlorine in pool water which can lead to bacteria and algae taking over in the pool. So it’s often better to address the problem of high alkalinity levels before they can cause more trouble.

If your pool alkalinity levels continue to become higher, it will become difficult to change the pH level in the pool water. You’ll know your pH is too high when your pool water is cloudy, there is scale build-up on your pool walls steps, and your chlorine in the pool is no longer successfully sanitizing your pool.

The process of properly re-balancing your pool water alkalinity can take more than one week, so be patient with this one.


  • High Chlorine and High pH in Pool

If the pH level in the pool gets higher than 7.8, the pool water is becoming too alkaline. When water is too alkaline in the pool, it reduces the effectiveness of chlorine, the pool chemical that kills pathogens. Pool water with a pH that’s too high and alkalinity out of range also can cause skin rashes, cloudy water, and scaling on pool equipment.

Having too much chlorine in your pool water can be dangerous. Exposure to high levels of chlorine can cause lung irritation, skin, and eye damage and have adverse effects on asthma. Not only is it bad for your health, but it can be bad for your pool due to the increase in chlorine.

If the pH or alkalinity, in fact, the elevated alkalinity may cause your ph level to rise, along with it being too high in the pool water, the disinfection power of your chlorine is affected. You’ll probably add more chlorine to compensate, and the problems with high alkalinity and pH will snowball. The answer:

  • Adjust water Alkalinity level 1st
  • Adjust higher pH level 2nd
  • Once the pool is balanced, adjust the pool water free chlorine level (FC)


If the pH is too high in the pool water, the disinfection power of your chlorine is affected. You’ll probably add more chlorine to compensate, and the problem will snowball.

The answer:

  • Adjust Alkalinity first
  • Adjust pH 2nd
  • Once the pool is balanced, adjust the free chlorine level (FC)


How do you Fix Low pH With High Alkalinity?

  • Recirculate pool with filter pump
  • Calculate acid addition
  • Add Muriatic acid diluted in a bucket of H2O & broadcast the acid around the pool
  • Retest after 6-8 hours
  • Once TA is 80-120 ppm
  • Aerate the pool with a compressor or pump to mix the contents adding air
  • Do this for 24-48 hrs.……………………………………………………………………………………………………Read more



What Causes Low Alkalinity in Pools?

  • Rain can be acidic
  • Increase in swimmer load
  • Topping your pool off with H2O that has low alkalinity-after backwashing/wasting
  • Chlorine-Chlorine is acidic
  • High H2O evaporation-losing H2O can dilute TA
  • Pool H2O agitation-H2O agitation increases the loss of CO2 affecting TA ……………………………………………….. Read more

Lower the Level of High pH & High Pool Alkalinity in Swimming Pool

*When Mixing Muriatic acid Never Pour Water Into Acid-Always Pour Acid Into Water!

  • Start with Total Alkalinity (TA), which is the basis for this water chemistry and pool maintenance 
  • Run pool pump on bypass filter- (Some people don’t agree with this and say they should keep the pool water pump off) Others like myself think the pool should be running
  • Calculate  doses of Acid addition with a Pool Alkalinity Calculator 
  • Mix and add Muriatic Acid in a bucket of pool water- the elevated alkalinity may cause your pH level to rise along with it-you need to lower it-there are 2 different strengths-(Use the stronger Muriatic Acid)
  • Evenly distribute the doses of acid by walking around the perimeter of the pool, broadcasting the diluted acid doses across the entire pool using gloves and goggles for protection.
  • Test pool water pH and Alkalinity test levels every 6-8 hours with a reliable test kit using instructions
  • If you have the pool pump off, wait for a little longer-then test pool’s pH levels
  • Adjust pool water pH with a pH increaser or use aeration to naturally lower pools alkalinity

Disinfection can be affected when the alkalinity level and chlorine level of water in the pool or spa are high. Regular doses of chlorine tablets and additional lbs of chlorine won’t work the same and hold the chlorine to a lower level.

If your Total Alkalinity levels are too low (below 80 ppm alkalinity) but pH levels are above 6.8, you will need to add an Alkalinity Increaser (sodium bicarbonate). When both Total Alkalinity and pH level in the pool or spa are too low (TA less than 80 ppm, pH below 6.8), use pH Increaser (sodium carbonate) to bring both levels up.

If your Total Alkalinity level in the water of your pool or spa is too high, add pH Reducer (sodium bisulfate) an acid to lower the pH of the water in the pool.

When Lowering a Total Alkalinity level in the pool or spa can be a lengthy, sometimes frustrating process, as sodium bisulfate will also have the effect of reducing the pH of the water in the pool at the same time as it lowers your Total Alkalinity of the water in your pool

You may need to make repeated adjustments for lowering alkalinity and then raising pH until both come into the proper range. No matter what adjustments you need to make, always retest the water in the pool or spa with test strips or a test kit before adding more chemicals to the water in the pool or spa.


If you need to raise water in the pool’s pH without affecting Total Alkalinity?

You can sometimes raise the pH level by aerating the water in the pool or spa. Just add air! It’s the same reason a pool, hot tubs, and spas often suffer from high pH level issues. Although this will raise your pH, it’s important to note that this isn’t an exact science, and results will vary by pool or spa.

You can aerate water in the pool or spa by bubbling air through the pool water, agitating the water in the pool surface, spraying droplets through the air with a pool fountain, or even just playing and splashing around the water in the pool. During the hot summer months, this method also can be used to lower pool or spa water temperature.

To keep high alkalinity from happening too often, because of too many chemicals use smaller increments of the chemical when adjusting alkalinity levels and test the water in the pool or spa every 24 hours until it reaches its ideal conditions.

Add Chlorine pH and Alkalinity to Daily Pool Maintenance


Instead of running chlorine, pH, and total alkalinity(TA) tests a few times a week as maintenance solutions schedule, try running a sample with a test kit every day as a regular guide until your swimming pool’s total chemistry and disinfection process in the pool water comes back to a balance.

Pay attention to levels of Total alkalinity levels and how they compare with other pool water tests. Once the alkalinity level in your swimming pool comes down, the rest of the test levels will look better. So will your pool water.

pH test results should be between 7.2-7.6

Free Chlorine (FC) should be 1.0-3.0 ppm

Total Alkalinity (TA) should be between 80-120 ppm

Use a reliable swimming pool test kit with reagents that are new and fresh.

Pool water test samples should be consistent


How do you Lower Alkalinity Without Lowering pH?

Running pool features, bubblers, sprayers, jets, & waterfalls, create turbulence that will remove CO2 faster raising the pool’s pH & when total alkalinity needs lowering without affecting the pH level, an acid is added, & the pool water is aerated to raise the pH level.…………………………………………… Read more


JimGalloway Author/Editor

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