FAQ
Possible causes of discoloured water are oxidizing impurities of a metallic nature such as copper, iron or manganese.
Iron and manganese, e.g. if well water is used as filling water. Iron and copper can originate from metallic installations such as pipes or heat exchangers in the water circuit if the water is corrosive (low pH value) or has been for a long time. Blue or green discoloration can be caused by the use of copper-containing algaecides (algaecides).
Recommended products
Cloudy water can have various causes and is the result of water-insoluble particles:
- Insufficient filtration, no or too infrequent filter backwashing
- The filter is not able to retain fine impurities. The use of flocculants makes these impurities filterable.
- Precipitation of calcium carbonate due to high calcium hardness and/or too high pH value.
- Algae formation. This type of cloudiness can be recognized by the fact that the wall surface of the pool feels slippery in connection with the cloudiness. This problem can be solved by shock chlorination or the addition of an algaecide (algae killer).
Recommended products
Foaming in the pool can be caused by overdosing an algaecide, for example. If foaming occurs, partially drain the water and replace it with filling water. Reduce the algaecide dosage or replace with a foam-free algaecide.
Recommended products
For algae to grow, they need warm water, sunlight, carbon dioxide or nutrients such as nitrate (produced from the breakdown of chloramines) or phosphate. Phosphate enters the water both via the filling water and through the people bathing.
The three important algae groups:
- Yellow algae: powdery precipitate at the bottom of the pool, largely resistant to chlorine.
- Black (blue-green) algae: Spots on the pool wall. Often grow in layers on top of each other, which means that the chlorine often only removes the top layer, allowing the other layers to survive.
- Green algae: the most common type. Usually floats in the water. Usually develops in places without circulation (e.g. due to poor pool flow).
Algae can be destroyed and algae growth prevented by using algaecides (algaecides). The black (blue-green) algae is usually somewhat more stubborn and requires additional cleaning with a brush.
Recommended products
Deposits on the pool wall can have various causes:
- Copper-containing algaecides: Copper deposits (blue-green or gray-black) occur especially with overdosing.
- Iron and manganese compounds: if the pool is filled directly with groundwater and in the presence of chlorine, brown (iron) and black-grey (manganese) deposits form.
- Iron and copper compounds: Can be dissolved out of metallic fixtures (e.g. pipes, heat exchangers, skimmers) by corrosive water (low pH value) and result in blue-green or gray-black deposits.
Recommended products
- Active chlorine (effective chlorine): The addition of chlorine or oxidizing chlorine compounds to water produces hypochlorous acid (HOCI).
- Free chlorine (HOCI): hypochlorous acid and hypochlorite anion are referred to as free chlorine. Chlorine in this free form is odorless, less irritating to the mucous membranes than combined chlorine in the same concentration.
- Calcium hypochlorite Ca (CIO)2: as a solid (granulate or tablet), measured content of Ca (CIO)2 at least 65%.
- Chloramine (combined chlorine): Chlorine-nitrogen compounds
- Chlorite: refers to salts of the chlorous acid HCIO2. In the chlorite anion (CIO2), chlorine has an oxidation number of +3. In this state, chlorite is a strong oxidizing agent and is easily decomposed.
- Chlorates: are salts of chloric acid HCIO3. In the chlorite anion (CIO3), chlorine has the oxidation number +5. Chlorates are strong and spontaneously reacting oxidizing agents.
- Sodium hypochlorite (NaCIO): chlorine bleach is also liquid and has an active chlorine content of 12-15%.
Recommended products
Chlorination is the addition of chlorine or an oxidizing chlorine compound to water. Chlorination is used for disinfection and to oxidize water constituents.
Recommended products
Sterilization (or disinfection) refers to the killing/removal of microorganisms, especially bacteria, fungi and viruses, by physical or chemical means.
Recommended products
First and foremost, disinfection serves to quickly kill all pathogens of transmissible diseases so that there is no risk of infection. These include, among others:
- Escherichia coli (E. coli): coliform germs and a typical indicator of fecal contamination.
- Pseudomonas aeruginosa: Bacteria that multiply optimally at a temperature of 20-42°C. Pseudomonas aeruginosa can form a slimy protective layer, which makes them particularly resistant to disinfectants. These bacteria indicate a lack of hygiene and disinfection of the water. They can cause skin, external ear and urinary tract infections.
- Legionella spec. (Legionella) These bacteria multiply rapidly at a water temperature of 35-55°C and can survive up to a temperature of 60°C. Legionella can lead to serious illnesses in humans, so-called Legionnaires’ disease and Pontiac fever, if ingested e.g. via aerosols.
Recommended products
The pH value is a measure of the strength of the acidic or alkaline effect of an aqueous solution. Derived from the Latin pondus Hydrogenii or potentia Hydrogenii (pondus = weight / potentia = strength, hydrogenium = hydrogen).
- pH < 7: Solution with acidic effect
- pH = 7: neutral solution
- pH > 7: alkaline solution (alkaline effect)
Recommended products
It is not only visible contaminants that get into the water, but also invisible contaminants (called colloids) such as bacteria, germs etc. (not water-soluble). Even highly effective filters cannot completely retain colloids. By using flocculants before filtration, these are destabilized (electrically discharged) and incorporated into the flocculates that form, which can then be retained in the filter bed. It is important that the flocculant is constantly added to the discharged water in order to achieve the best possible result, to use the right flocculant and the correct dosing quantity.
If flocculant is not used correctly, flocculation can occur in the pool water. This can be easily recognized by opalescence (with iron-containing agents: green coloration of the water) or strong clouding of the water.
