Ensuring clean and safe water in a swimming pool is of utmost importance. Before disinfection, mechanical filtration must be performed to remove large particles and debris. After this stage, disinfection methods such as chlorine-based chemicals or ultraviolet (UV) treatment can be used. So, which is the better option—chlorine-based disinfectants or UV radiation?
Mechanical filtration – the primary stage in water treatment
Before beginning the disinfection process, it is essential to perform mechanical filtration, which includes:
- Filtration – The primary method for removing solid particles and suspended matter from water. The water passes through specialized filters that trap contaminants.
- Skimming – The process of removing organic films and debris from the water surface.
These procedures significantly improve water quality, reducing the number of pollutants and enhancing the efficiency of disinfection systems.
Chlorination of swimming pools
The use of chlorine-based disinfectants is one of the most common methods of pool disinfection. Its key advantages include:
- Long-lasting effect – Chlorine remains active in water for an extended period, killing microorganisms and preventing their growth on pool surfaces.
- Concentration standards – The free chlorine level should be at least 0.3 mg/L, and in combined systems, at least 0.1 mg/L. The bound chlorine level should not exceed 0.2 mg/L. These levels are sufficient to eliminate bacteria and viruses, but excessive chlorine can negatively affect human health.
- Complexity of operation – Chlorination requires constant monitoring of chemical levels, regular maintenance of pumps, and checking for equipment corrosion.
- Impact on humans – High chlorine concentrations may cause skin and mucous membrane irritation.
UV sterilization of swimming pools
Ultraviolet (UV) radiation is increasingly used as a safe and eco-friendly method of pool water disinfection. The key features of this method include:
- Immediate effect – UV light effectively destroys microorganisms by damaging their genetic material, preventing their reproduction.
- No residual effect – Unlike chlorine, UV treatment does not provide lasting protection. The disinfecting effect stops as soon as the water exits the UV exposure zone.
- Ease of maintenance – UV systems require minimal maintenance, mainly periodic cleaning of quartz sleeves and lamp replacement.
- Health safety – UV treatment does not leave behind chemical residues, making it harmless to skin and eyes.
Comparison of chlorine and UV disinfection methods
| Characteristic | Chlorine | Ultraviolet |
| Effectiveness against germs | High | High |
| Service | Requires constant monitoring | Easy service |
| Duration of effect | Long-term effect | One-step impact |
| Effect on human | Can be irritating | Safe |
Both chlorine and UV disinfection methods have their advantages and limitations.Chlorine provides continuous protection against microorganisms but requires regular monitoring and maintenance. UV systems are easy to use and safe but do not prevent water from becoming contaminated again after treatment.
Combination of chlorine and ultraviolet
A combined method allows for a significant reduction in chlorine concentration, minimizing its negative effects on human health. UV radiation effectively kills harmful bacteria and viruses, while also reducing the formation of byproducts such as trichloramines (compounds that cause skin, eye, and respiratory irritation).
Using UV treatment, the residual chlorine level can be reduced to 0.1 mg/L. This approach helps lower chemical treatment costs, which is especially important given the rising prices of disinfectants.
A combination of both methods ensures maximum water disinfection efficiency. UVL offers a wide range of flow-through UV sterilizers for pools, including UVL-AQUA and medium-pressure UV sterilizers or large pools, ensuring effective pool water purification.
