Slow Chlorine Tablets 200 g - 1 kg

These 200 g slow-release chlorine tablets provide ongoing disinfection for swimming pools as the tablets gradually dissolve in water. Supplied in a 1 kg pack, they are intended for routine maintenance of swimming pools containing more than 20 m³ of water.

Formulated with symclosene (trichloroisocyanuric acid), the tablets help maintain an appropriate free chlorine level and prevent algae growth.

What are 200 g slow-release chlorine tablets used for?

Slow-release chlorine is designed for regular pool disinfection rather than occasional shock treatments. The tablets release chlorine progressively, helping maintain disinfectant levels between water treatment checks.

This product offers several practical features:

• Gradual chlorine release: suitable for routine pool water maintenance.

• 200 g tablets: intended for pools over 20 m³, as specified on the manufacturer’s label.

• 1 kg pack: a convenient supply of tablets for ongoing maintenance.

• Stabilized chlorine: the active ingredient also contributes cyanuric acid (CYA) to pool water.

Because stabilizer can accumulate with repeated use, it is important to monitor CYA levels. Learn more in our guide to pool stabilizer and cyanuric acid.

How much slow chlorine should you use?

What dosage does the manufacturer recommend?

The manufacturer specifies one 200 g chlorine tablet for a swimming pool containing more than 20 m³ of water.

Before use, check the following parameters:

• Water pH: between 7.0 and 7.4.

• Free chlorine: between 1.5 and 3 mg/L.

• Application: in a skimmer or suitable floating chlorine dispenser.

• Filtration: adjusted according to the water temperature.

This is the manufacturer's stated dosage for pools over 20 m³. It should not be converted automatically into a proportional dosing rule for every pool size.

When another tablet is required depends on the water measurements and the treatment recommendations provided by the iopool app.

How to use slow-release chlorine tablets

1. Test your pool water. Check the pH and free chlorine concentration before applying the treatment.

2. Adjust the pH. Make sure it is between 7.0 and 7.4, as indicated on the label.

3. Choose a suitable dispenser. Place the 200 g tablet in the skimmer or in an appropriate floating dispenser, following your pool equipment instructions.

4. Run the filtration system. The label recommends daily filtration hours equal to half the numerical water temperature in °C. For example, water at 26°C requires 13 hours of filtration.

5. Avoid direct contact with pool surfaces. Never place a chlorine tablet directly onto the pool liner.

6. Remove the floating dispenser during swimming, as instructed by the manufacturer.

7. Monitor free chlorine. Maintain the level between 1.5 and 3 mg/L.

8. Replenish when necessary, according to the iopool app's recommendations and the manufacturer's instructions.

How do 200 g tablets differ from other chlorine formats?

The 200 g tablets are designed for gradual chlorine release in pools that meet the volume specified on the label.

For spas and smaller water volumes, a more appropriate format may be required. Discover the 1 kg pack of 20 g slow-release chlorine tablets, which must be used according to its own instructions.

Shock chlorine serves a different purpose. It is intended for rapid, occasional disinfection when corrective treatment is needed, rather than continuous maintenance.

Product specifications

Safety precautions and storage

DANGER — Oxidizing chemical hazardous to health and the environment.

• May intensify fire, is harmful if swallowed and causes serious eye irritation.

• May cause respiratory irritation and is very toxic to aquatic life with long-lasting effects.

• Wear protective gloves, protective clothing and eye protection.

• Never mix with other chemicals. Contact with acids may release toxic gases.

• Never place two different treatment products in the skimmer or treatment system at the same time.

• Never pour water onto the product.

• Avoid direct contact with pool liners, vinyl, polyester and painted surfaces.

• Do not use with bromine or PHMB treatment systems, as stated on the label.

• Keep the product in its original, tightly closed container, locked away from children, protected from moisture and sunlight, at temperatures between 5°C and 25°C.

• Dispose of the contents and packaging according to applicable regulations. Do not release the product into the environment.

Always read the full product label before handling or use.

Manage your pool treatment with the iopool app

The free iopool app provides personalized treatment recommendations based on your pool's water conditions.

For manual checks of free chlorine, pH and stabilizer, use iopool 6-in-1 pool test strips.

The app helps you decide when further treatment may be needed while keeping the manufacturer's dosing and safety instructions as the reference.

Frequently asked questions

Are these 200 g chlorine tablets stabilized?

Yes. They contain symclosene, a stabilized form of chlorine. Regularly monitor cyanuric acid levels to avoid excessive stabilizer buildup.

Can these 200 g tablets be used in a hot tub or spa?

This product is labelled for swimming pools containing more than 20 m³ of water. For spas and smaller volumes, choose a treatment specifically intended for that use.

How often should I add another chlorine tablet?

The label does not specify a fixed replacement interval. Follow the iopool app's treatment recommendations, free chlorine measurements and manufacturer instructions.

Can I use these tablets with a cartridge filter?

Yes. The manufacturer's label confirms compatibility with filtration systems, including cartridge filters. Make sure the skimmer or dispenser is suitable for your installation.

Use biocides safely. Always read the label and product information before use.