For water that is always clear and healthy, it isn’t enough just to filter it. It also has to be treated in order to remove viruses and bacteria. Quality water must not only be disinfected but also disinfecting - we talk of a remanent effect - because, although the bathers’ hygiene may be irreproachable, this will not prevent bacteria from being brought into the pool. There are several efficient water treatment products.
Chlorine: this is the most widely used product. Extremely active, it efficiently removes bacteria, viruses and micro-organisms as well as algae. However, its effectiveness declines with high pH levels - pH is the unit used to measure water acidity - and it is very UV sensitive.
Bromine: less sensitive to UV and temperature than chlorine, it is widely used in spas. It has the advantage of remaining active at high pH levels.
Active oxygen: completely water-soluble - it breaks down into water and oxygen - it will not cause unpleasant side effects such as red eyes and skin irritation. Nevertheless, it needs to be combined with an anti-algae product to supplement its action.
PHMB: PolyHexaMethylene Biguanide has no effect on algae which means that they have to be treated separately. UV-stable, it remains effective even when faced with temperature or pH variations and imparts no taste or smell to the water. However, it can have a corrosive action on equipment and is still expensive to use. Moreover, it is only compatible with sand filters.
UV: water is subjected to intensive UV radiation that destroys bacteria, viruses and algae and sterilises the water. Not sensitive to the chemical variations affecting water and especially pH, this effective treatment does not, however, have any remanent effect. Therefore, it has to be supplemented by, for instance, active oxygen.
Electrolysis: this is a form of treatment using chlorine and has a particularly interesting cycle. The salt contained in the water is converted into chlorine under the action of an electric current. Chlorine has the advantage of being highly reactive and especially of not producing chloramines which create smells and, occasionally, allergies. Chlorine reforms to produce salt and so forth. The result: salt consumption reduced to an absolute minimum. Electrolysis equipment has the advantage of being autonomous which means that the treatment can be programmed. If they don’t already have one, we recommend that they be combined with pH control systems because they tend to raise the pH.