In theory, in a well chlorinated and well balanced swimming pool with a well distributed circulation system, algae shouldn't grow. However, in practice these single-cell and multicellular plants are frequently seen to grow, in both outdoor swimming pools and indoor ones. Algae in swimming pools are unsightly but are not harmful to bathers. However, if they are not quickly removed they can form a focal point that encourages the growth of bacteria and fungi in the water. It is in fact difficult to maintain a constant and equal chlorine concentration in all parts of your swimming pool.

To protect your swimming pool and control the proliferation of common algae, use hth Kontral.

For water in swimming pools that is subject to a lot of movement (powerful filtration systems, underwater currents, jets, etc.), we recommend that you usehth Kleral, a special non-foaming algicide.

Usinganti-algae products such as hth Kleraland hthSuper Kleral together with chlorine in the right quantities prevents the growth of algae when a dose of ¼ of a litre per 25 m3 of water is used as a preventive treatment.
For a curative treatment, allow 1 litre per  25m³ of water and at the same time deliver a shock chlorination with a fast-dissolving chlorinated product suitable for your regular treatment (preferably hth Granularor hthShock).

Warning: never mix products in their solid form.

Some algae found in swimming pools such as mustard algae, black algae and pink algae are particularly resistant, even to chlorine (up to 5 mg/l). In this case only hth Blackal shock is effective thanks to its formula, which contains copper.
Pour in 1/4 litre of hth Blackal Shockper 25 m³ of pool water. Pour the product directly into the water (it is essential that bathers are not present), dispersing it around the pool as much as possible, with the filter running.
Tip: it is best to usehth Blackal Shockin the evening.

In tiledswimming pools you can use CARRAL®, which also removes mould from the tile joints. Apply the product near the area to be treated, either with a length of plastic hose or by sprinkling it directly onto the water at the base of any undesirable stains.
Use 10 to 15 g of CARRAL® per m³.