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Purpose of a Pool Stabilizer

Satyajeet Vispute Feb 24, 2019
A pool stabilizer is a supportive element used for effective pool-water maintenance. In this Gardenerdy post, we shall find out what does a pool stabilizer do, and also figure out how much of it should be used to achieve the best results in pool cleaning.

Did You Know?

Certain types of chlorine products such as dichlor and trichlor tablets are pre-stabilized. This means that they already have a certain part by weight of stabilizer added to them, and therefore, using additional stabilizers becomes unnecessary.
Outdoor swimming pools are stagnant bodies of water. They are exposed to all the external elements, and therefore, are prone to getting contaminated. Hence, a little chemistry needs to be performed to keep the water in swimming condition.
An important ingredient in this is a swimming pool stabilizer. It supports and helps other chemicals in the pool to keep the water clean. In the following lines, we shall see what a swimming pool stabilizer is, and also how we can use it to help keep our pools clean. But first, let's find out why it is required to be used in the first place.

Why Use a Pool Stabilizer

The chemical of choice used for disinfecting the water in swimming pools and Jacuzzis is chlorine. It is harmless to human beings, but is potent enough to kill many different microorganisms and bacteria that breed and grow in stagnant water.
On being added to water, chlorine chemically reacts with it and breaks down into hypochlorous acid (HOCI) and hypochlorite ion (OCI). Both these chlorine derivatives attack the cellular structure of the microorganisms and destroy the enzymes inside, which ultimately oxidizes them, that is, destroys them.
However, HOCI is very unstable in the presence of sunlight, and quickly dissipates on exposure to it. This causes the chlorine that you have added to an outdoor swimming pool to quickly disappear, unless a pool stabilizer is used to prevent this from happening.

What Does a Pool Stabilizer Do

Cyanuric acid is the most commonly used chemical that is added to swimming pool water, to help prevent the chlorine loss on exposure to sunlight. It is popularly known as a pool stabilizer, conditioner, or CYA.
Cyanuric acid forms a weak bond with chlorine atoms, thereby shielding it from the UV rays of the sun, while at the same time allowing it to carry on with its original function of disinfecting the water in the pool.
If used in the right amount, cyanuric acid can check the chlorine-loss, and reduce the amount of chlorine that is required to keep the water clean. This can significantly save on the maintenance cost of the pool.

How to Add a Pool Stabilizer

Pool stabilizers in the market are in the form of white-colored granules or powder. These can be directly added to the water or pumped through filtration system. In the first method, the powder is diluted in a bucket of water before adding it to the water. Though it is the easiest way, it is not efficient at distributing the stabilizer throughout the pool.
The second method allows for faster distribution. In it, the pool filter is put into the backwash mode to clean it thoroughly. Then the filter is put into the normal operation mode, and stabilizer granules are added to it through the pool skimmer. The stabilizer flows through the internal pipes of the system until it reaches the filter element.
Since stabilizers dissolve slowly, it remains on the filter element until it breaks down enough to flow through it and into the pool. To speed up the process, one can even turn on the pool heater (if available), as stabilizer particles are known to dissolve quicker in warm water.

How Much Should Be Used

Adding very little stabilizer to the pool won't be enough for protecting the chlorine from the UV rays of the sun. Adding too much of it will slow down the rate at which chlorine reacts with the water, thus reducing its water-cleaning efficiency. Therefore, for optimum performance, balance needs to be maintained.
The amount of stabilizer in water is measured in parts per million (ppm). If 'x' ppm is added, it literally means that the water contains 'x' parts per million parts of water. It has been observed that, under normal conditions adding less than 30 ppm of stabilizer turns out to be less, while adding more than 60 ppm can be too much.
So obviously, the ideal range is 30 to 60 ppm. For instance, you can add 3 pounds of stabilizer per 10,000 gallons of water, which constitutes to about 36 ppm. For regions which receive a lot of sunlight, the ideal range can be extended to between 40 - 80 ppm.

Caution About Overuse

It is important to remember that stabilizers do not leave the pool water unless they are splashed out or forced out through back-washing. If one just keeps adding more stabilizers without first removing the previously added one, it can severely hinder the chlorine's ability to disinfect the water.
A typical example of overuse of stabilizers is when the pool water turns cloudy. This is the result of a process called chlorine-lock, wherein chlorine is unable to react with the water and convert to HOCI. Hence, before adding more stabilizer, one must replace the water in the pool partly or completely with freshwater and chlorine.
Another lesser-known fact is that, most commercially available chlorine tablets already have stabilizers added to them. In such cases, externally adding a stabilizer will also amount to overuse.
Thus, by adding an appropriate quantity of stabilizer to the water in a swimming pool, we can ensure that the expensive chlorine stays protected from sunrays, and is better able to perform its job of disinfecting the water.