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In order to enjoy visually crystal-clear water and a hygienically safe garden pool environment during the hot summer months, adequate use of chemical agents for water maintenance is necessary in addition to regular physical cleaning.

The best known of these are certainly the influencing of the pH value by raising or lowering it, or the use of chlorine or another selected disinfectant.

A factor that should not be underestimated is the so-called alkalinity, which in many cases is equated with the pH value, although it is another additional and at the same time very important aspect of pool chemistry, which is not the same as the pH value.

Just as with other utilities, it may happen that the pool alkalinity is too high, so it is necessary to bring about a lowering of the same. If the value is too low, you need to increase the alkalinity.

In the following sections, we will not only discuss the effects of too high alkalinity, but also explain with the help of instructions how to lower this value again.

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Reasons why you need to lower the pool alkalinity

Increased alkalinity has a variety of effects, mainly due to the fact that this factor is significantly linked to the behavior of the corresponding pH value and keeps it at a stable level.

Often, therefore, a high pool alkalinity will be found in a less than optimal pH, although this need not always be the case. Due to the fact that, for example, the selected disinfectant sometimes does not develop its effect optimally with an unbalanced pool chemistry and that additional negative effects can occur, it is essential to lower the increased alkalinity again accordingly.

Why is the alkalinity in the pool too high?

Both a modification of the chemical composition of the water in a swimming pool and changes in natural conditions can cause a fluctuation in the alkalinity in the pool, whereby this not only affects the pH value, but an increasing pH value also causes the alkalinity to increase.

Potential causes for this can be, on the one hand, a water supply that already has a high alkalinity from the start, or on the other hand, it is possible that the increase in the PH value indicates, among other things, the presence of sweat or lotions for personal hygiene.

Furthermore, an increase in alkalinity may also occur as a result of shock chlorination due to the highly alkaline nature of the pool shocker.

Effects of too high a Ta value.

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Since an ideally adjusted alkalinity protects the pH value of the pool water from occurring fluctuations, it is important to maintain the optimal value, which, depending on, for example, the usage behavior when bathing or the location or size of the respective pool, can vary between 80 ppm to 160 ppm (parts per million or milligrams per liter).

One effect that occurs in many cases when the so-called Ta value is too high is that the pH value is also difficult or impossible to lower.

In the case of the phenomenon known as over calcification, it is also conceivable that the water in the pool becomes increasingly cloudy, there is a strong spread of lime both on the components of the pool and on the pool accessories, or there is irritated itchy skin or burning eyes.

Step by step, lowering the pool Ta level (instructions)

In the event that excessive alkalinity is confirmed by the presence of an elevated Ta value, it is highly recommended to readjust the pool chemistry to an ideal level as soon as possible to avoid any negative effects.

In order to bring about an appropriate reduction in alkalinity, a few steps are necessary, which will be explained in more detail in the following sections.

Step 1: Measure the pool alkalinity

The first step is to determine the pool alkalinity, using methods ranging from simple test strips to specially designed kits and digital meters.

Once you have read the TA value, you will be able to estimate how much the pool alkalinity is elevated, as an ideal value should be between 80 ppm and about 120 ppm or 160 ppm (parts per million or milligrams per liter).

Step 2: Decide on a product

Next, there are a number of options or products to choose from to lower the alkalinity of the pool water, including products from the manufacturers Chemoform or Bayrol. What all these aids have in common is that they are either already acidic or form some kind of acid, which inevitably lowers the alkalinity.

Depending on the situation, these include, for example, the use of pH-Minus as granules and in liquid or powder form, the use of muriatic acid, also known as hydrochloric acid, and the addition of sodium bisulfate, which is also known as dry acid, although the use of the latter is only recommended in exceptional cases.

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Step 3: Calculate the required amount

Due to the fact that depending on the individual characteristics of the chosen product, it is not reasonable to make general statements regarding the dosage, one should consult the enclosed instruction manual in order to achieve a promising result.

If, after using the product, you are still in doubt about the correct amount, you can either discuss the issue with other pool owners or seek a professional opinion elsewhere, indicating the size of the pool, the weather conditions, the location and the determined PH value, in order to avoid undesirable side effects.

Step 4: Prepare the product

Depending on whether you have chosen a liquid or a powder product or one in the form of granules, the individual preparation differs a little from each other, so it is necessary in any case to consult the appropriate instructions before use.

Especially in the case of a product that is in the form of a concentrate, but also in the case of numerous other auxiliary products, mixing with water in a separate bucket is usually carried out before proceeding with the final step.

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Step 5: Add the product to the water

After preparing the product according to the individual instructions of the respective manufacturer, it is essential to add the product to the water of the pool in several places.

In addition, it should be ensured that the pool pump is put into operation at the same time in order to guarantee optimal distribution of the active ingredient. As a rule, it is advisable to let it run for several hours afterwards.

What is the difference between alkalinity and pH?

When dealing with chemical water care, you will often hear pH used interchangeably with alkalinity, although these are two different factors. The pH value is used to determine whether the corresponding pool water can be considered acidic or alkaline, with the number 7 corresponding to the neutral value in the middle.

However, the alkalinity or the total alkalinity is not usually indicated using the pH scale, but in the unit of measurement ppm, which stands for parts per million, which in German means milligrams per liter.

Despite the fact that pH and alkalinity are in principle not dependent on each other, in many cases there are similarities in that they are often either both high or low, although this is not necessarily always the case.

While pH is a fundamental aspect of pool chemistry, alkalinity, in a sense, serves to maintain it at a consistent level by performing a neutralization of the acids contained in the pool’s water. Assuming that there is a pH below the number 4.3, it is not yet possible to determine alkalinity of the pool water, since it does not yet occur at such a value, the water is therefore considered to be classified with zero alkalinity.


Alkalinity or total alkalinity is an often underestimated factor in chemical pool maintenance, even though it is instrumental in maintaining pH levels at a stable level in particular.

Assuming that it increases for various reasons, corrosion phenomena, lime deposits or other undesirable side effects can occur, which is why you should lower the TA value again as soon as possible.

This is possible without problems in five simple steps with the most diverse products, whereby one must always take into account the individual situation on site as well as the characteristics of the individual aids with the application.

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.