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People who have just bought their first pool are not yet aware of the tasks and duties that come with owning a pool.

Namely, in addition to cleaning the pool with a pool brush and pool vacuum, pool owners must also regularly test the pool water and constantly adjust the pool chemistry.

When testing the pool water, you need to pay particular attention to the chlorine concentration and pool pH. Many people who have just purchased an inflatable swimming pool need to learn what pH means and how to test pool pH.

Reasons why you need to raise the pool pH

A too low pool water pH can lead to serious problems. The effects of low pool pH include irritation of the eye, skin and especially mucous membranes, as well as possible damage to pool equipment and pool materials.

So, if the pool water is acidic, it has adverse health effects, but it can also be really expensive if, for example, costly elements of the filtration system are damaged.

In this guide, we explain how to raise pool pH in our practical step-by-step format. The guide is intended for all pool owners who have used pool test strips or a digital pool tester to conclude that the pool pH is too low.

We recommend that every pool owner first take a closer look at pool pH. It is important to understand what pH is and what the effects of an incorrect value will have on the pool and pool water. In a comprehensive pool pH guide, we go into all the details on this topic.

For those who don’t have the time to read right now, here’s a quick summary:

The pH value (short for Potentia Hydrogenii) tells you what properties a substance has. In our case, this means how alkaline or acidic the pool water is. The scale of the value ranges from 1 to 14, with a value of 7 being considered neutral. Values above 7 are referred to as alkaline or basic water, while pool water below a pH of 7 is acidic.

The pH of the pool water should be between 7.0 and 7.4. Anything outside of this range can harm either the bathers, the pool equipment or the pool materials.

Why is the pool pH too low?

A pool pH that is too low is extremely rare. This is because it can only occur at all due to rainwater and other foreign particles.

Rainwater: The most common reason for a low pool pH is rainwater. In Germany, rainwater has an average pH value of 5.6 to 5.8 and is therefore in the acidic range.

Rainwater ends up in any pool that is not covered with a pool cover. The effect of rainwater on pool water can vary greatly. How acidic the rain is depends on how much acid is washed out of the air. The simple but best protection against acid rainwater is to cover the pool before each downpour.

Foreign particles: Various foreign particles in pool water can be the cause of low pool water pH. Foreign particles can get into the water through people, animals or other outside influences.

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A first preventive measure is to fish all visible foreign bodies out of the water. This can be done well with a pool landing net, for example.

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Dirt particles that have sunk to the bottom are best collected with a pool vacuum. If you like, you can also invest in a pool robot. These small devices independently scour the pool (and sometimes the pool walls) and vacuum up all debris.

Effects of a too low pool pH

A pool pH that is too low manifests itself in ways that every pool owner would like to avoid. The following are the effects that low pool water pH can have:

  • The respiratory system and mucous membranes become irritated.
  • The pool materials (especially tile joints and metal parts) are damaged by corrosion.
  • The chlorine content of the water cannot be maintained (thus the disinfecting effect decreases).
  • The effect of the flocculant decreases.
  • The pool may produce an unpleasant odor.

Increasing the pool pH step by step (with pH Plus granules)

Also, who observe one or more of the listed effects, should refrain from premature conclusion. The problem is not necessarily that the pH is too low. In fact, some consequences of a pool pH that is too low overlap with those of a pool pH that is too high.

Therefore, you should neither raise the pH across the board nor lower it. What matters is that the pH is in the optimum range of 7.2 to 7.6. In this range, the pool chemistry is in balance, the pool equipment will not be damaged, the pool water is hygienically clean and swimming in the pool is completely harmless to health.

In order to increase the pH of the pool water, pH Plus granules are most often used. In the following instructions, you will learn how to proceed step by step.

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Step 1: Determine the pool pH

A simple method to determine the pH level in the pool, is to use pool water test strips. The method is not the most accurate, but for that, the test strips are quite cheap and easy to use.

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Basically, you proceed as follows.

  1. Hold the test strip in the water for about 10 seconds.
  2. Then take it out. (Without shaking off the test strip).
  3. Compare the resulting color with the table on the container.
  4. Read the pH value at the point where the colors match.

Note: Besides measuring with test strips, there are more accurate ways you can measure pool pH. However, the better accuracy also comes with a higher price. Digital meters are the most accurate.

Step 2: Determine the capacity of the pool

If you don’t know the capacity of the pool, you’ll need to do some math. But don’t worry – it’s quite simple.

Depending on the shape of your pool, different formulas are used to calculate the volume:

(units in meters)

  • rectangular pool = length x width x average depth
  • round pool = diameter x diameter x average depth x 0.78
  • oval pool = length x width x average depth x 0.89
  • eight-shaped pool = length x width x average depth x 0.85

Note: The (estimated) average depth is the average of the deepest and shallowest points in the pool. Simply measure the depth at the deepest and shallowest points, add the two numbers and divide by 2.

If your pool is a different shape, you can divide the pool into sections. Next, calculate the volume of each section and then add all the volumes together.

The conversion from cubic meters to liters is very simple: just multiply the m³ by 1000.

Here is a small calculation example to illustrate:

For a rectangular pool with the dimensions

length = 6 m
width = 4 m
depth = 2 m

the resulting volume is 6m x 4m x 2m = 48m³.

The resulting number of liters is 48m³ x 1000 = 48000 liters.

Step 3: How much pH Plus granulate is needed?

Next, the amount of pH Plus Granules needed must be calculated.

Here again a small formula is used:

To increase the pH value by 0.2, you need to add 4.5 g of pH Plus Granules per 1000 liters.

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For a water volume of 48000 liters this would be 216g pH Plus Granules:

48000 liters / (1000 liters / 4.5 grams) = 48 x 4.5 grams = 216 grams of pH Plus Granules.

Now you have to compare the result with your measured value. If you measured a value of 6.8, you would have to use twice the amount of pH Plus Granules to get into the optimal range of 7.0 – 7.4.

In fact, if you want to increase the value from 6.8 to 7.2, it will take twice the amount of pH Plus Granules. So the calculation is:

7,2 – 6,8 = 0,4 = 2 x 0,2

2 x 216 grams = 432 grams of pH Plus Granules

Step 4: Add the pH Plus Granules to the water

For the best possible effect, you should ensure circulation in the pool. Therefore, turn on the pool filter. Alternatively, you can also use a landing net to provide some movement in the pool.

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It is best to dissolve the pH Plus Granules in a bucket beforehand. Fill a large bucket with at least 4 liters of water, add the pH Plus Granules and stir the mixture a little.

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Do not pour all the liquid in the same place, but spread the dissolved granules in the water by walking around the pool when pouring.

Raise the pool pH with household remedies

In addition to the efficient method with pH Plus granules, there is also the possibility of raising the pH level with household remedies. Basically, you proceed in the same way as when raising the pH with pH Plus Granules.

The only difference is that you use washing soda instead of the granules and adjust the amount. Washing soda can be purchased at specialty stores, but there are usually cheaper deals online.

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To increase the pH by 0.2, you will need about 5g of soda per m³ of water. Make sure that you always raise the pH gradually and that there is always water circulation in the pool.


Maintaining a pool involves quite a bit of work. In particular, pool owners must always keep an eye on the pH level of the pool and adjust it if necessary. At first, this can be a bit of a challenge. However, once you master the basics, you will have no trouble with this part of pool maintenance in the future.

In this article, you have learned not only how to recognize a pool pH that is too low, but also how to raise it.

We hope we were able to help you and wish you a clean pool with a great pH in the future!

Larry has been a true water rat since childhood. Pure pleasure turned into a passion. That's why he is the first point of contact for friends and acquaintances when it comes to pool-related problems. He is an integral part of the PoolHandbook editorial team.