How to Use Chlorine Tablets in Your Pool to Prevent Algae?

Chlorine tablets are helpful to keep your swimming pool clean. But how are chlorine tablets used in a pool, and how is the chlorine dosed in the form of tablets?

The best way to use chlorine tablets is to use a floater or a chlorine metering sluice. Alternatively, the chlorine tablet can be dosed into the skimmer, with a loss of effectiveness of 20%. 2 chlorine tablets of 200 g each are necessary per week in a swimming pool.

This article explains how to use chlorine tablets in your pool like a pro. I will also explain how to avoid a too high chlorine level in your pool water.

How to use and dose chlorine tablets

Chlorine is available in different forms, and each type of chlorine requires other methods on how to use it.

Chlorine granulate is sprinkled directly into the pool, and many beginners assume that the chlorine tablet is also placed directly in the pool.

But this is fundamentally wrong and not a common method!

Adding chlorine tablets directly to your pool will cause bleaching spots in the swimming pool.

Furthermore, an overdose of chlorine in your pool is expected if the chlorine tablets are not correctly dosed. This leads to burning eyes, milky pool water, and other disadvantages.

In the next chapter, you will learn the best ways to use chlorine tablets in your pool and how to dose them.

1. Use the floater to dose the chlorine tablets

The best way to add chlorine tablets to your pool is to use a floater (also known as a dosing floater).

The chlorine tablets are slowly and continuously dissolved in the plastic container. The advantage is that free chlorine is constantly generated in your pool.

Another advantage of using a pool floater is that the chlorine consumption is reduced by 20% compared to a skimmer.

It is important that the floater hangs in the flow of the return nozzles of your pool and does not float freely in the water – a simple string is sufficient.

The floater ensures that the chlorine is evenly released into your pool water. This method will also prevent stains in your pool caused by chlorine tablets.

But how are chlorine tablets used and dosed in a pool?

The floater always remains in your pool, and it is only taken out of the water when you need to refill it.

But take care: Chlorine should never be touched with bare hands. This also applies to chlorine tablets!

Use gloves or, as an alternative, a small plastic bag to help you grip the chlorine tablet.

If the free chlorine level in your pool is too low, simply put more tablets in the floater.

A regular water test will tell you whether adding more chlorine tablets to the floater is necessary.

Info: A floater is unsuitable in a PVC liner or vinyl pool as it will cause bleaching stains. In this case, it makes more sense to use the skimmer instead of the floater.

2. Use chlorine tablets in the skimmer and the pump

Most private pool owners chlorinate the pool using a skimmer. And still, others put the chlorine directly into the pump.

The problem with this is that the effectiveness of the chlorine from the skimmer is reduced up to 20%.

The result is: In the summer, the chlorine consumption increases, which leads to increased costs for your pool maintenance.

If you are using a PVC liner or a vinyl pool, this is a common method for using chlorine tablets in a pool.

It is difficult to dose chlorine tablets precisely, but dosing directly via the skimmer or the pump means that the maximum dose of chlorine in your pool is more often exceeded.

However, over time and through regular water tests, you will get a sense of how many chlorine tablets are necessary for your pool.

You should keep one thing in mind when using the chlorine tablets in your skimmer or the prefilter of your pool pump.

When the chlorine tablet rests in the basket, an aggressive chlorine solution is produced, which has a corrosive effect on your pump and can lead to damage.

Tip: As is often claimed, there does not have to be solid chlorine in your skimmer to produce free chlorine. The attentive pool owner uses cyanuric acid as a chlorine stabilizer or already stabilized di-chlorine or tri-chlorine.

3. Automatic chlorine metering sluice

The chlorine in your pool can be easily dosed with a dosing aid (chlorine dosing sluice).

If you want to handle chlorine tablets as little as possible, then a chlorine metering sluice can help to reduce the water treatment in your swimming pool.

However, an additional installation is necessary because the chlorine metering sluice must be mounted on the suction pipe in front of the pump.

The dosing aid is charged with chlorine tablets and adjusted with the help of water tests until a level between 0.3 and 1.5 ppm of chlorine in your pool is reached.

The optimal levels ​​can vary depending on bathing habits, weather, and your location – in some regions of the US, the limit level for chlorine is 2.0 ppm.

But is the installation of the chlorine metering sluice recommended?

If you have the option of using a floater, then use this. In all other cases, the chlorine metering sluice would be preferable to use.

Info: Some advisors recommend installing the chlorine metering sluice after the pump. As a result, the water should pass through the dosing aid at the end until it is rinsed back into the basin.

4. Other ways of using chlorine tablets

The best ways to use chlorine tablets in your pool are:

  • With the help of a floater
  • Right in the pool skimmer
  • In the basket of the pool pump
  • By using a chlorine metering aid.

The purpose of the chlorine tablet is the ongoing production of free chlorine in your pool.

However, chlorine tablets can also be used differently.

The chlorine tablet is applied in a targeted manner. For example, when black algae occur locally in your pool – you can read exactly how this works in my post about black algae.

Why do you need chlorine for your swimming pool?

Chlorine belongs to the group of halogens and is used in solid, liquid, and gaseous forms in a pool.

Compared to other disinfectants, chlorine is cheaper and more effective.

That is why chlorine is one of the most common methods of water treatment in private and public pools.

Compared to other forms, chlorine granulate in particular is the cheapest and most common for private pool owners – alongside chlorine tablets.

The important thing here is the generation of free chlorine.

The free chlorine eliminates germs, bacteria, and algae in your pool. This keeps the water clean and makes bathing more pleasant for all bathers.

Furthermore, if it is correctly dosed, unpleasant smells (chloramines) are eliminated with chlorine.

An incorrect dosage in your pool does not only lead to unpleasant smells and clouding of your pool water. Allergies and chloracne can also occur.

You can find out how to dose the chlorine tablets in the following chapter.

How many chlorine tablets should I use in my pool?

The concentration of chlorine in a pool differs depending on the region and location of your pool.

But how high should the chlorine concentration be?

The ideal level of chlorine in your pool is 0.3 to 1.5 ppm. In some regions of the US, it is often said that the chlorine level should be between 1 and 3 ppm.

Stick to my recommended levels. These are ideal for keeping your pool clean and preventing cloudiness.

In the end, as a pool owner, you have to decide what works best for your swimming pool.

But, how many chlorine tablets are needed in your pool on average in the summer, and how often should you add the chlorine tablets to your pool?

I recommend about two tablets of 200g/week. Extrapolated to the year, this is 50 to 60 chlorine tablets, corresponding to 10 – 12 kg.

Depending on your pool size, buying chlorine tablets from 5 kg containers and always having them in stock pays off.

To ensure that the ideal free chlorine level is available in your pool, you should check the water levels ​​with test strips 1 to 2 times a week.

If there is enough free chlorine in your pool, there is no need to put an extra chlorine tablet in the floater or your skimmer.

You would only risk an over-chlorination in your swimming pool.

What is unique about chlorine tablets?

Not all chlorine is created equal. It was briefly mentioned that different types of chlorine exist, and there are reasons for that.

But what is special about chlorine tablets, and what is meant by free chlorine?

Free chlorine is the chlorine that is used to disinfect your pool.

And that is exactly what chlorine tablets are good for: The ongoing generation of free chlorine in your swimming pool.

After the chlorine reacts with sweat, urine, or other contaminants, it creates bound chlorine.

The combined chlorine is still effective but not as good as free chlorine.

Info: The total chlorine level is calculated by summarizing the free and bound chlorine.

But the tablet form also makes it easier to use chlorine. Dosing is becoming increasingly automated, especially through the installation of a chlorine sluice.

You can get different sizes of chlorine tablets in pool shops, but which one is the right one?

The right chlorine tablet for your pool maintenance

Chlorine tablets are available in different sizes. The tablets with 200-300 g are particularly recommended here.

The larger tablets are easier to use when dosing in your pool and, extrapolated to the weight, are cheaper.

A chlorine tablet of 300 g is usually sufficient for 30 m³ of water, but pay attention to the manufacturer’s instructions.

This data can determine exactly how many chlorine tablets are needed in your pool. All you have to do is calculate your pool volume.

Tip: If you plan to use the chlorine tablets in a floater, be sure to use a floater in which large tablets fit. If necessary, the small chlorine tablets can also be dosed into these.

Questions and answers about chlorine tablets

Did I leave out your question about the chlorine tablet in this article?

I am pretty sure you will find the right answer here.

Where do the chlorine tablets go in?

Chlorine tablets work best when they are used in the floater.

In the floater, the tablets work up to 20% longer. This saves costs and is more effective for disinfecting your pool.

How long does it take for the chlorine tablet to dissolve?

Depending on the manufacturer and the size of the chlorine tablet, these dissolve differently.

A 200-300 g chlorine tablet can hold in your floater for up to 1 week. This means that you should add a new chlorine tablet to the pool every week.

Are chlorine tablets suitable for a pool shock?

Chlorine tablets are intended to produce free chlorine in your pool continuously and are therefore not suitable for a pool shock.

For a swimming pool shock, the chlorine level must be quickly raised to a high level in order to remove all impurities – That is not possible with a chlorine tablet.

What is better. Chlorine tablets or chlorine granules?

A comparison between chlorine tablets and chlorine granulate is only possible to a limited extent.

While the chlorine tablets can continuously produce free chlorine, the chlorine granulate quickly loses effectiveness if it is not stabilized with cyanuric acid.

Furthermore, a pool shock and local algae control are possible with the chlorine granulate, for which a chlorine tablet is not suitable.

In practice, a combination of chlorine tablets in your floater and chlorine granulate is recommended.

What is better, chlorine tablets or liquid chlorine?

Liquid chlorine is best suited for a pool shock. Liquid chlorine is also available as stabilized chlorine, which can disinfect a pool over the long term.

Nevertheless, a chlorine tablet is better to produce free chlorine with the help of a floater.

Here, a combination of chlorine tablets and liquid chlorine is advisable.

Which chlorine tablets are best?

There is a wide variety of different manufacturers of chlorine on the pool maintenance market.

You should test on your own which one works for your pool maintenance.

And where can you buy chlorine tablets?

You can get chlorine tablets at your local pool store and online. Online shops provide a wide selection of different manufacturers.

Tip: The chlorine tablets are a little cheaper on the Internet than in the pool store.

How should I store the chlorine tablets?

Chlorine is best stored in a dry and well-ventilated place.

The storage location should be in the shade to protect the chemicals from heat.

Always store your chlorine in the original packaging and avoid repackaging. You can read more tips on chemical storage in my guide.

Do you have any further questions about chlorine or especially about chlorine tablets?

Use the search function or contact me via Twitter @contactswimfool.

Have fun using the pool chlorine tablets!

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Hi. I'm Max Berg. I've been in the pool industry since 2015 and have always felt drawn to water. I'm the author behind swimfool.com, where I share my years of experience in pool maintenance and give helpful tips on keeping a swimming pool or hot tub clean. My tips reduce the costs of water treatment and protect the environment.

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