How to Lower Pool pH (With 2 Simple Methods)

How To Lower Pool pH


If you are a pool owner, then you know that managing its pH is a never-ending cycle. Sometimes it is high and at times it goes lower than the required level (7.2-7.6). That said, if the pH is too high, there are two procedures that you can use to lower it.

In this article, we will look at these two procedures plus the tips to use to keep the pH level balanced. Let’s get started.

Why is Your Pool’s pH High?

Treating Low pH

If you added pH raising chemicals to the water when it was too low, chances are that you might overdo it and cause the water to have a high pH level.

High pH Water Supply

The most common reason is the water supply. Most municipal water supply systems have slightly alkaline water in the pipelines, and this is not accidental.

If they don’t treat the water like this, it might be slightly acidic, which would cause corrosion damages along the way. As such, if you use this water for your pool, it can raise the pH gradually as you refill it.

Why Should You Lower Your Pool’s pH?

Why Should You Lower Your Pool’s pH

1. Causes Skin and Eye Irritation

Just like water with low pH levels, high pH causes skin irritation. It also causes stickiness, which can be very uncomfortable. As for the eyes, they have a pH of around 7.2 and anything above this will cause some discomfort and irritation.

2. Causes Cloudiness

Perhaps one of the most noticeable things about high pH levels in water is cloudiness. This is not dangerous in itself but the water won’t be very inviting to swim in.

Read More: Why is my Pool Cloudy?

3. Causes Chemical Imbalance

Chlorine is the main chemical used for sanitizing pool water. However, it only works effectively if the pH is balanced at the required range of 7.2-7.6. Therefore, if the pH is too high, chlorine might not be very effective.

If this happens, algae and other contaminants will start to increase, causing the water to be very unhealthy to swim in. To eliminate this problem, you will require more chlorine to sanitize the water, which translates to more dollar signs on your pool’s maintenance tab.

4. Causes Scaling 

Lastly, this water condition causes scale build-up, which can result in clogging along the pipes, filters, and other sections in the circulation lines.

This reduces the system’s flow rate while increasing its pressure, and this strains the pool pump. The result is a shorter pump lifespan plus leaks along the lines due to the increased pressure.

How to Lower Pool pH

Tips for Keeping pH Levels Balanced

Photo: Gettyimages

1. Using Sodium Bisulfate

For this method, you will need a test kit and sodium bisulfate, which is usually called dry acid because it is in powder form.

  • Begin by testing the water’s pH level using the test kit. This will help you determine the amount of acid that you need to add to the water. You can use either test strips or the reagent type, but we recommend the reagent kit type.
  • Measure the volume of your pool. For every 10,000 gallons of water, you need about 2 lbs. of the acid to lower the pH by 0.2 points. However, this is a rough estimate. You should use the manufacturer’s instructions on the label to determine the required ratio.
  • Since it comes in a powder form, pour the dry acid while very close to the water surface. Be very careful during windy conditions because the acid can be blown to your eyes or skin. Ideally, you should pour the acid while holding it downwind.
  • For better distribution, pour in the acid around the water return jets because the water coming into the pool will do the work for you.
  • The chemical should dissolve in about 10 minutes but you should wait for about 6 hours for it to work its magic before testing. It is important to note that this acid can also lower alkalinity and therefore, you have to test both parameters.
  • If the pH is not at the optimal range, repeat the process from step 3.

2. Using Muriatic Acid

With this method, you still need a testing kit plus muriatic acid.

  • Determine the amount of acid that you need by measuring your pool’s volume and testing the pH level. Read the manufacturer’s instructions on the label to determine the exact quantity that is required.
  • Just like when using dry acid, pour in the acid very close to the water surface and avoid standing downwind. It is very harmful and corrosive to the skin.

To minimize the chances of lowering the alkalinity level:

  • You can funnel the acid to the bottom of the pool. First, turn off the pump then leave the water to become still for an hour. After this, pour in the acid at one spot so that it sinks to the bottom. Muriatic acid has a much greater effect on alkalinity at the surface and therefore, funneling it to the bottom will only gently lower the pH level. After about an hour, turn on the pump to circulate the acid.
  • Alternatively, you can pour in the acid at the water return jets, with the goal here being even distribution. A high acid concentration at one point might also lower the alkalinity, which will need more chemical balancing work.

After treating the water, let the acid do its work for about 6 hours before doing another test.

If the pH is not low enough to the optimal level, repeat the process from step 2.

Note: Muriatic acid is very corrosive. You should wear protective gear when handling it. You may even have to dilute it before use but this should only be done if specified by the manufacturer.

Because of its highly corrosive nature, make sure you don’t accidentally pour the acid on any concrete or masonry work around the pool or in the storage area. This may corrode and damage the surfaces.

Usage Tips

  • Since the process requires strong, corrosive acids, don’t pour them around the skimmer or any other inlet sight. This is because the strong, undiluted acid will be sucked into the pool’s pump, heater, and other equipment, causing expensive damages.
  • Most test kits can only measure a high of 8.6 points on the pH scale. Therefore, if your pool’s pH level is too high, you need to use muriatic acid or any other pH reducer to bring it down to a measurable level. You will know this if the test kit seems not to be working.
  • Even though they are all acids, they come from different manufacturers and have different concentration levels. As such, you must read the manufacturer’s instructions on how to use and application ratios for a proper pH lowering treatment.
  • For above-ground or sports pools (which are shallow), pour in the acid from different sections around the perimeter for better distribution. After this, circulate the water manually to eliminate concentrated spots, which can lower alkalinity.

Tips for Keeping pH Levels Balanced

1. Test the Water as Often as Possible

Usually, twice a week is enough but the more the better. This will help you monitor the water conditions closely and apply small fixes before the situation gets from bad to worse.

2. Shock your Pool

This should be done more frequently if your pool is under high usage. The process sanitizes the water more effectively and balances the chemistry levels. That said, under normal use, the water should be shocked at least once a month.

Read More: When to Shock your Pool

3. Maintain cleanliness

This is a no brainer. Any debris or contaminant has the potential to alter your pool’s pH level. Thus, you should skim off the leaves and use a pool vacuum cleaner to keep the water crystal clear. You should also check the filtration system regularly to ensure it is working optimally.


Balancing your pool’s pH level is an essential part of pool maintenance and lowering it if too high is part of the process. However, we recommend being proactive and taking the necessary steps to keep the pH balanced to avoid going through the tedious balancing process above.