As soon as we start heating the water and the sun comes out, algae growth can start in your pool. Algae are plant microorganisms that provide a breeding ground for bacteria. When they proliferate, they first cause aesthetic problems (cloudy, greenish water), which, if not treated properly, can lead to fibrous, clumpy or gelatinous material floating in the water, which can be physically disturbing and quickly render the sand filter unusable.
Apart from the fact that some algae can pose a direct threat to our health, the biggest danger of algal blooms is that the algae that grow in the water consume the disinfectant, allowing dangerous bacteria to multiply.
I. ROOT CAUSES:
The combination of the following factors leads to algal growth:
- Strong sunshine
- Plunging water: points in the pool where the disinfectant-containing water does not move, concentration is reduced: corners, steps, lamp covers, counterflow surfaces.
II. CURRENT SITUATION:
- In the early stages, algae growth is difficult to detect, with black or yellowish spots appearing on the surface of the water
- Opalescent water colour, which may be the result of the onset of algae growth!
- Slippery surfaces
- Various, typically green, patches appear on the pool wall, with both light and dark-loving algae species appearing.
Algae can easily become resistant to chlorine, so the use of an algaecide is recommended for effective removal.
III. PREVENTION, TREATMENT:
THE BEST METHOD AGAINST ALGAE IS PREVENTION! Regularly add an algaecide (ALGI-CID or CHLORALGIN) to the pool, and clean and vacuum the surfaces: this will make it more difficult for algae to adhere. Frequent monitoring of disinfectant concentrations can also help to detect problems early.
Anti-algaecide dosing: once a week, ALGI-CID or CHLORALGIN will prevent algae from colonising.
A sudden decrease (disappearance) of the normal disinfectant concentration may indicate that algal growth has started in the pool water. In this case, ensure that the disinfectant is replenished and add an anti-algaecide as a routine treatment.
Regularly de-soiling surfaces with a pool vacuum cleaner: it is more difficult for algae to settle on the cleaned surface.
Extra rinsing of the sand filter: after a large number of guests or after rainfall, it is advisable to rinse the sand filter in addition to the normal rinsing.
TYPE OF ALGAE:
GREEN ALGAE: the most common algae species in swimming pools. It occurs in places where circulation is poor (e.g., corners). Once established, it proliferates explosively.
For chlorine disinfection: add 0.5 kg of ALGA-SHOCK P granules per 10 m³ of water, then circulate the water and vacuum the pool.
Local treatment of algae: spray ALGA-SHOCK P directly on the algae surface. The resulting particles destroy the algae layer stuck on the surface, which is then easily removed.
For chlorine-free disinfection: : the shocking can be carried out as above with ALGA-SHOCK P, but the Dewan dosage must be interrupted for the duration of the operation. After the shocking, only when the chlorine level has been reduced to
below 1 mg/l (the two agents cancel each other out)
MUSTARD ALGAE: another typical algae species of pools, yellowish-brown or “mustard” in colour.
It can be easily removed from walls with a brush, but quickly returns. It prefers shady areas with poor water circulation. Resistant to chlorine and shock.
Algi-Cid is recommended for removal.
BLACK SPOTTED ALGAE: A highly resistant algae species that adheres to the pool surface and floor. It gets its name from the fact that it forms tiny, black spots or patches.
If present in the pool for a longer period of time, it is more difficult and time-consuming to remove.
Treatment should start as soon as it appears by brushing it thoroughly.
PINK SLIME: typically found around ladders, steps, pool lights, skimmers and other areas with poor water circulation. It is a bacterial (not algae) culture that gets its name from its colour and the fact that it makes surfaces slippery and slimy. It can be easily removed from walls with a brush. It can be distinguished from ‘pink staining’ by the fact that the pink slime can be removed by scrubbing. It can settle in many places, so check light fittings, surfaces under ladders, stair treads, filters, and plastic fittings.
Brush thoroughly first, then apply ACTIBON in a shock application, and then in weekly doses thereafter.
ALGAECIDES
ALGI-CID: quaternary ammonium active, broad-spectrum algaecide liquid.
CHLORALGIN: benzalkonium chloride-based agent with quaternary ammonium additive. General purpose algaecide liquid.
ALGA-SHOCK P: For local treatment of algal growth. The granulated product can be sprayed on the algae surface for a quick effect. It is applied by hand, directly onto the algal surface, before vacuuming. The pool should not be used during the shocking period!
CATEGORIES OF COMMERCIALLY AVAILABLE ALGAECIDES
Chlorine-based products: ineffective on some algae, usually requiring additional chemical treatment
Benzalkonium chloride-based products: algaecides available in large quantities and at low prices, with a narrow spectrum of action and, like chlorine, limited action on certain algae.
Quaternary ammonium-based products: very broad-spectrum algaecides, correspondingly in the higher price range, but with efficacy far exceeding that of the previous type.
Mixed formulations: containing some proportion of both types of algaecides, the price increases proportionally with the amount of quaternary ammonium.
What could be the reason why the algae still do not disappear from the water despite repeated shocking and continuous algae removal?
The presence of phosphates in water plays an important role in the growth and nutrition of algae. When phosphate levels rise above 100 micrograms per litre, algae growth problems begin. Phosphate levels can be checked with a dipstick or tested in a laboratory. If phosphate levels are above 400 micrograms per litre, algae removal should start by reducing phosphate levels to 0. In about 50 % of cases, this treatment will solve the problem without any other agent. Two of our products are suitable for reducing phosphate levels. For more information on their application, click on the link DINAX FOSZFÁT MINUS EXTRA or DINAX FOSZFÁT MINUS NORMAL (liquid).
Contact us by email or phone to solve your public swimming pool algae problems.
Our recommended products are available on the link below: