How Do I Fix High pH In My Pool?

Is the pH level of your pool out of control, and you wonder how to bring down the level? If the answer to this question is yes, then there’s no need to fret as this is a common problem for pool owners.

Speaking generally, it is essential to maintain a balance between acidity and alkalinity in your pool. However, the purpose of this article is to tell you ways on how to fix this common problem.

First thing first, what is pH?

Power hydrogen or pH, as it is commonly referred to, is a measure of how acidic or basic (alkaline) water is or the measure of total acidic-alkaline balance. The balance range of pH level in a pool is between 7.4 and 7.8, a higher number translates to more alkaline in the pool; also a lower number translates to more acids in the pool.

Causes of high pH in pool

The normal range of a balanced pH level is considered to be within 7.2 and 7.8. Maintaining such balance is not always easy. The pH level is a very volatile factor in water and very difficult to keep under control. This is because it is affected by almost everything that enters the water. Let’s highlight some of them.

  • Loss of carbon dioxide (CO2)

Several factors influence the CO2 (carbon dioxide) levels in the pool and cause the pH level of such pool to rise. Carbonic acid (H2CO3) is formed when carbon dioxide (CO2) dissolves in water (H2O): CO2 + H2O = H2CO3. This carbonic acid keeps the pH level in water low.

However, carbonic acid is lost when the water is disturbed for instance; through splashing or bubble escape. So the loss of carbonic acid will lead to higher pH levels.

  • Misuse of chemicals and sanitizers;

Sanitizing and pool shocking requires the use of several chemicals and sanitizers. However, chemicals or sanitizers used to sanitize the pool and dispose of chloramines could also influence the pH level of the pool.

Some chemicals or sanitizers are alkaline and tend to increase or raise the pH levels. Sanitizers or chemicals like HTH Granular and other liquid chlorine increase the pH level of the pool. So it is important for proper measurement and application when adding chemicals or sanitizers to your pool.

Aside from the factors listed above, an increase in temperature or a spike in the temperature of the pool water could lead to an increase in the pH level of your pool. That is, exposing your pool to direct sunlight can cause the pH level to increase.

Effect of high pH level

Suppose the pH level of your pool exceeds 7.8. In that case, it means the pH level of your pool is high and that the alkaline in your pool is high and reduces the efficiency of the chlorine/sanitizer (the chemical that kills the pathogens). Hence, your water is now too soft. This can be detrimental to both the health and pocket of pool owners. Some of the effects are stated below:

  • Cloudy water

Pools with an unbalanced pH level would result in the water looking cloudy. When the total alkalinity (TA) in the water is very high, the water becomes cloudy. This is a result of calcium scaling caused by the lack of balance created by the high alkaline. A high pH level also reduces the effectiveness of chlorine and causing scale deposits to form in the pool.

  • Irritable red eyes

The power hydrogen of the human eyes is between 7.2 to 7.4 so when the human eyes are exposed to a significantly higher level of pH it leads to irritation and redness. Swimming in the pool with high pH levels would lead to irritable red eyes. This explanation dispels the popular myth that irritable eyes cutting from swimming pools is a result of too much chlorine in the water. Of course, too much chlorine can irritate the eyes, but it is not always caused by high chlorine levels.

  • Clogged filters

Pool owners that make use of sand filters would discover that with high pH levels the sand in the filters, sand particles, and scale would coat together and could form lumps. This may solidify into a hard mass.

The filter would no longer be effective and it would fail to trap contaminants and dirt from the pool. Hence, leading to plumbing failure which in turn would cost the owner more money to maintain.

  • Wear and tear of swimwear and increase chlorine usage

Swimwear such as goggles and bathing suit quickly or prematurely wear and tear. Also, the amount of chlorine used in a pool with a high pH would increase. A pool with a high pH level would require about four times the normal dosage it would require in a normal or balanced pool for it to be effective, therefore, increasing the cost of maintenance.

How to lower pH levels in your pools

Before you proceed on lowering your pool’s pH level it is important to carry out a proper test using a pool test kit to check or determine the pH level. After the test is carried out and the pH level results are high, you can now restore balance.

  • Pick a chemical of choice (the most commonly used chemicals are sodium bisulfate and muriatic acid) and spray or spread evenly in the pool, it is advisable to make use of a pool calculator to get the accurate amount of acid or sodium you need for the process.
  • Leave the pool to aerate naturally without making use of any aerator like air compressors. This process helps raise the pH level when it is low.
  • Test water in intervals, say after every 6 hours, then test the water after 24hours, and finally, check the balance of all chemicals after 48 hours. Hopefully, the pH level would then be balanced.

As stated earlier, there is two common product used for lowering the level of pH in a pool. These are sodium bisulfate and muriatic acid.

Here are what you will need and the steps for each product.


What you will need

  • Sodium bisulfate: This is also called dry acid; it comes in powder form. So it is best to avoid using it on a windy day. It is a much less corrosive chemical than muriatic acid, and a bit safer to administer, so some people would prefer this to muriatic acid.
  • Accurate pool water test kit: A proper and very accurate test kit is needed for this procedure. Accurate and precise test readings would make this process much easy.
  • Protective gear: This chemical is not corrosive and is in powder form, but do make use of gloves, goggles, and other protective gears when handling it to avoid it entering the eyes and coming in contact with your skin.

Steps in lowering pool pH level with sodium bisulfate

Step 1

Read instructions of the product, because different manufacturers could have different percentages of sodium bisulfate. While some might recommend you dilute the dry acid first.

Step 2

Find how much of the sodium bisulfate you will need to apply based on the results from your test (remember to always use an accurate test kit). It is advisable to proceed with caution as you would want to avoid excess usage. It is advisable to use 3/4 of what is recommended

Step 3

Sodium bisulfate is in powder form, so apply downwind from you. This is done in other to avoid getting the acid on your cloth or skin. It is better to make use of this chemical on a non-windy day. Get as close to the water as possible and spread the powder to avoid the wind blowing the powder into the air instead of the pool.

Step 4

Add it over the water return jet sights. These are portals that push the water around the pool. Avoid adding it at the skimmer areas and other inlet sights. Try to spread the sodium bisulfate as much as you can around the pool.

Step 5

No need for aerating the pool, or trying to mix the powder around the water by hand because sodium bisulfate or dry acid will dissolve on its own after 5 to 10 minutes period

Step 6

Test the water after some time, say after 6 hours, and then proceed to test the water after 24hours of adding the last dose of the sodium bisulfate.


What you will need

  • Muriatic acid: This is also called hydrochloric acid. It Is also used to wash ceramic tiles. Usually, muriatic acid comes in a liquid form and is more corrosive than sodium bisulfate. Highly popular in the market because it has a lot of commercial use. With caution, muriatic acid is highly recommended to be used in pools.
  • Accurate pool water test kit: A proper and very accurate test kit is needed for this procedure. Accurate and precise test readings would make this process much easier.
  • Protective gear: This chemical is highly corrosive, making use of gloves, goggles, and other protective gears when handling it.

Steps to lower your pool pH using muriatic acid

Step 1

Read the product’s instructions and its usage carefully because the product is highly corrosive and can burn the skin and damage the pool surface if not properly used. Never forget to always wear your protective equipment; safety they say can never be overemphasized.

Step 2

Find how much of the muriatic acid you will need to apply based on the results from your test (remember to always use an accurate test kit). It is advisable to proceed with caution as this acid is very corrosive and you would want to avoid excess usage. As a newbie to this process, it is advisable to use 3/4 of what is recommended and test the level of pH again until you get satisfied with the level.

Step 3

Follow the manufacturer’s instructions to dilute the muriatic acid and add it to water and avoid dumping this into any inlets. There are two major ways of adding muriatic acid to water; either you funnel it to the bottom or you spread it around.

The two major ways to administer muriatic acid both have valid points, so we will discuss them one after the other

Funnel it to the bottom

To effectively lower the pool’s pH and alkalinity level, it is advised to ensure the pool is calm and still (switching off the pumps) for about an hour. Then administer carefully the muriatic acid into the pool to avoid splash – focus a steady stream in a particular spot in the pool.

This will then flow gradually to the bottom of the pool and steadily lower the pH while not affecting the bulk of surface water. Then wait for a while after adding the muriatic acid before turning the pump on.

This method is recommended because muriatic acid tends to have a greater effect on the surface alkalinity of the pool, so this gets the muriatic acid to the bottom of the pool where it will not influence the alkalinity much.

Spread It Around

The popular way to add muriatic acid is to place yourself near the pool return jets, which is where the water is injected into the pool. Place yourself very close to the water to avoid spillage or droplets of muriatic acid on the pool surface.

Drop the acid in the deep end of the pool, avoid water inlets and return lines, then pour slowly in one area. Move to the next and pour. Try to spread evenly and avoid a higher concentration of acid in any area of the pool.

Muriatic acid quickly disperses as it has already been diluted in water before application. Wait for 6 hours to give the pool time to adjust to the chemical then carry out a test to check the pH level. Retest again after 24 hours.


Maintaining balance in all things is very important in life and pools are not an exception. Knowing how to maintain pH balance in pools is an important skill that pool owners should have. It is a continuous process, so try as much as possible to monitor your pool as its pH level can easily be influenced. Once you notice any abnormal pH level, don’t hesitate to correct it to avoid damages to your health as well as time and money.

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