Common
Pool Problems

Under the relevant regulations, commercial swimming pools are required to have a responsible manager.

At Valentek Water Technologies, we meet the required qualifications and provide responsible-manager services to commercial pool operators. We support regular monitoring of pool water in line with health and operating criteria, the review of records, and the coordination of technical processes.

Our approach is not limited to meeting regulatory requirements. We evaluate water chemistry, analysis results, disinfection, filtration and chemical management together, with the aim of supporting more controlled, traceable and sustainable pool operation.

Cloudy pool water can have many different causes. Rather than trying to solve the problem simply by adding chemicals, the possible causes should be assessed systematically so that the root cause can be identified.

The quality of the source water should be evaluated first. Pool filling water is required by the Ministry of Health to be of drinking-water quality. If the source water does not meet this quality, metals and other components in the water may cause persistent cloudiness.

Another important factor is swimmer hygiene. Swimmers should shower before entering the pool and ensure foot hygiene in an appropriate disinfection area. Children should also avoid remaining in the pool for more than two hours at a time, both for their own health and to help prevent unwanted incidents.

Cloudiness caused by swimmer load would normally be expected to clear within approximately 6–8 hours when the chemical balance is correct and the filtration system is operating properly. If the problem continues, a hydraulic, filtration or chemical-management deficiency should be investigated.

Sand filters that have lost effectiveness, inadequate filter maintenance, an imbalanced pool chemistry or insufficient shock chlorination can all lead to persistent cloudiness.

In outdoor swimming pools, pH should be maintained between 7.2–7.4 and free chlorine between 1–3 ppm. If the chemical parameters are appropriate but cloudiness continues, the filtration system should be assessed in detail.

In short, cloudiness should not be attributed to a single cause. Source water → swimmer load → water chemistry → filtration and hydraulics should be evaluated in sequence to determine the real cause.

A swimming pool can be one of the most important architectural features highlighting the appearance of a property. However, green pool water is not only a visual problem; it may also indicate that the water is no longer under adequate microbiological control.

Greening indicates that microbiological growth has begun. This does not by itself mean that illness will directly result, but it does indicate that there is not enough free chlorine in the water and therefore insufficient disinfection protection against potentially harmful microorganisms.

A green pool should not be used. Pool surfaces should be brushed mechanically, the filtration system should run continuously, and an appropriate shock-chlorination procedure should be applied.

Using more chlorine than necessary during shock treatment is also not correct. Excessive chlorination may cause staining on tiles, surface problems and shorter equipment life.

During shock treatment, free chlorine should not exceed 10 ppm. As measured free chlorine is consumed, enough chlorine should be added to bring it back to 10 ppm, while the filtration system runs continuously.

The goal is not simply to make the pool look blue again, but to eliminate the chemical or operational problem that caused the greening.

Contrary to a common belief, a strong chlorine smell in a pool is not a sign of hygiene.

The formation of combined chlorine, together with stabilized chlorine use, swimmer load and organic contamination in the water, may lead to the formation of chloramines and trihalomethanes.

When combined chlorine is not removed adequately, the characteristic “chlorine smell” commonly associated with swimming pools develops.

A strong chlorine smell therefore may not mean that there is too much effective chlorine in the water. On the contrary, it can indicate that chlorine has reacted with contaminants and lost effectiveness.

Measuring the combined chlorine level and applying the correct shock-chlorination procedure when required are key steps in resolving the problem.

Regular use of stabilized chlorine products, particularly chlorine products at 56% and 90% concentration, increases the cyanuric acid level in pool water.

Despite what its name may suggest, cyanuric acid is not harmful by itself. In outdoor pools it also performs a useful function by reducing the rate at which chlorine breaks down under sunlight.

However, when dichlor and trichlor products are used continuously, the chlorine they provide is consumed over time while cyanuric acid continues to accumulate in the pool water.

Excessively high cyanuric acid can lead to the condition commonly described as “chlorine lock,” which is associated with reduced disinfection effectiveness of chlorine.

In this situation, the required amount of pool water is drained and replaced with fresh water so that the cyanuric acid level falls below the Ministry of Health’s stated upper limit of 100 ppm.

Afterwards, conditioning should preferably continue with liquid chlorine to help prevent cyanuric acid from accumulating again.

Although pool water may appear still, it is actually a continuously changing dynamic chemical system. Dissolved ions, source water, rainfall, swimmer load and the chemicals being used all affect pH.

Even in a pool balanced through routine checks, pH may fall after a rainy week or change after heavy use due to sunscreens, lotions and other swimmer-related contaminants.

A pH of around 7.4 provides a comfortable swimming environment for the human eye and skin.

Correct pH is important not only for swimmer comfort. It also supports chlorine remaining in the hypochlorous acid form that is effective against microorganisms, thereby improving disinfection efficiency.

For this reason, pH is not simply a value to correct when it becomes problematic; it is one of the core operating parameters that should be monitored regularly.

In areas where mains water hardness is high, especially when a pool is operated at high pH for extended periods, the water’s saturation index can rise and cause scale formation.

Scaling typically appears as white or light-coloured mineral deposits on pool surfaces, tiles, overflow channels and equipment.

One of the most effective ways to prevent scale is to keep the pool water’s saturation balance under control and, in particular, to monitor pH regularly.

As with every water parameter, both high and low values can cause problems. Low pH may negatively affect swimmer comfort and equipment, while high pH can accelerate scale formation and reduce the disinfection effectiveness of chlorine.

The aim is therefore not simply to correct one parameter, but to maintain the overall chemical balance of the pool water.

Because of Türkiye’s climate, many outdoor and unheated swimming pools are not used during the winter months. At the end of the swimming season, the pool should therefore be prepared correctly for winter and closed for the season.

In some applications, pools are completely drained at the end of the season and refilled the following year. However, leaving a pool completely empty for a long period is not a correct practice.

The weight of water in a full pool helps the structure remain balanced against the hydrostatic pressure created by groundwater. When the pool is left empty for a long period, this balance may be disturbed.

In reinforced-concrete pools, this can lead to cracking of the concrete structure or tiles becoming detached. In prefabricated and fiberglass pools, groundwater pressure may in more serious cases even cause the pool shell to move upward out of the ground.

Winter preparation should therefore be treated as a planned procedure in which the water and equipment are prepared in a controlled manner for winter conditions, rather than simply draining the pool completely.