Chlorine for Pools: Types, Dosage, and Mistakes You Should Avoid This Summer

Why is chlorine so important in your pool?

Chlorine is the most widely used disinfectant in the world for pool water treatment. Its function is to eliminate bacteria, algae, viruses, and other microorganisms that can be harmful to health. Without the correct level of chlorine, the water can become cloudy, green, and potentially dangerous for swimmers.

At Nousitan, we work with the best disinfection products for pools, including floating dosing tablets and products from the brand Astralpool, a European leader in water treatment.

Types of chlorine for pools: which one do you need?

There are several formats of chlorine on the market, each with its advantages and ideal applications:

Granular chlorine (powder)

This is the fastest acting. It is used for shock chlorination when the water is green or very dirty. It dissolves quickly and raises the chlorine level immediately. Ideal for seasonal start-up treatments or urgent recoveries.

Chlorine tablets (trichloro)

These are the most popular for daily maintenance. They are placed in a floating dispenser or in the skimmer and dissolve slowly, releasing chlorine consistently. The Astralpool Blue Line 69668 Floating Tablet Dispenser is perfect for this use, with a capacity of up to 3 tablets of 200g.

Liquid chlorine (sodium hypochlorite)

More economical and easy to use, but it degrades faster with sunlight. Ideal for large or frequently used pools where manual dosing control is desired.

Stabilized vs. unstabilized chlorine

Stabilized chlorine (with cyanuric acid) is more resistant to UV rays from the sun, so it lasts longer in the water. Unstabilized chlorine acts faster but is consumed more quickly. For outdoor pools in summer, stabilized chlorine is the best option.

Optimal chlorine levels in the pool

Maintaining chlorine at the correct levels is essential. The recommended parameters are:

The pool analyzer: the key to getting it right

To control chlorine accurately without the need for manual tests, the Analyzer Astralpool Blue Connect Gold 71663 is the perfect solution. This connected device measures free chlorine, pH, temperature, and salinity of the water in real-time, sending alerts to your smartphone when any parameter goes out of the optimal range. It is the ideal tool for anyone who wants to have the perfect pool with minimal effort.

Common mistakes when using chlorine that you should avoid

Mistake 1: Adding chlorine with swimmers in the water

Never add chlorine (in any form) while there are people in the pool. Concentrated chlorine can irritate the skin, eyes, and mucous membranes. It is best to add it in the late afternoon or evening and let the pump circulate for several hours before swimming.

Mistake 2: Not checking the pH before chlorinating

If the pH is above 7.8, chlorine loses up to 80% of its effectiveness. Always adjust the pH before adding chlorine to maximize its disinfecting effect.

Mistake 3: Exceeding the recommended dosage

More chlorine is not better. An excess (more than 3 ppm) can irritate the skin and discolor swimsuits. Always follow the manufacturer's instructions.

Mistake 4: Storing chlorine improperly

Chlorine should be stored in a cool, dry place away from direct sunlight. Heat and humidity degrade it quickly. Never mix different types of chlorine: it can cause dangerous reactions.

Frequently asked questions about chlorine in pools

How often should I add chlorine to the pool?

With a floating tablet dispenser, every 7-10 days during the summer. If you use granular chlorine for maintenance, every 2-3 days. In times of high heat or heavy use, increase the frequency.

Can I swim right after adding chlorine?

You should wait at least 4-8 hours after adding liquid or granular chlorine, and measure that the level has dropped to less than 2 ppm before swimming.

Does chlorine help eliminate green algae from the pool?

Yes, but it is more effective to combine it with a specific algaecide. Green algae require a shock treatment with high chlorine (5-10 ppm) and brushing of the walls, followed by intensive filtering for 24-48 hours.

Conclusion: the right chlorine + the right dispenser = perfect pool

Choosing the right type of chlorine and using it correctly is the foundation of maintaining any pool. At Nousitan, you will find everything you need: dosing tablets, Astralpool floating dispensers, and smart analyzers to keep your water always in perfect condition with minimal effort.