Step-by-Step Guide to Pool Water Treatment
If possible, use mains tap water to fill the pool, as this significantly simplifies the initial water treatment processes, making it much smoother to set the disinfectant level and pH value within the desired range. The use of well water or collected rainwater is not recommended, as their chemical and physical properties fundamentally differ from treated drinking water. Treating such alternative water types is a much more complex and less economical task, as their quality can change radically by region, which may necessitate extra, specific steps beyond the basic water treatment routine.
Maintaining crystal-clear pool water relies heavily on the continuous removal of mechanical impurities, as well as professional water circulation, which is essential for the homogeneous mixing of chemicals. The complete water circulation system consists of a high-performance pump and a filter tank. Quartz sand or premium glass media are most commonly used as filter media, while paper cartridge solutions are also widespread for smaller-scale pools.
Step 0: Ensure the Physical Cleanliness of the Water:
- Removal of surface and floating debris:
- Larger leaves and branches floating on top of the water can be lifted out manually using a practical leaf skimmer net, while the built-in skimmer (surface skimmer) is responsible for automated cleaning.
- Finor particles suspended within the water volume are filtered out by the water circulation equipment.
- Heavier dirt that has settled to the bottom of the pool can be effectively removed with a manual vacuum cleaner or a fully automated robotic pool cleaner.
The 5 Golden Rules of Water Treatment:
- Precise adjustment of the optimal pH value
- Continuous disinfection (via chlorine or active oxygen procedures)
- Preventive and blocking anti-algae treatment
- Fine flocculation (coagulation)
- Regular maintenance and inspection
1. Establishing the Chemical Balance of the Pool Water:
Pool water can only become sustainably transparent and hygienic if the various chemical components are in perfect harmony with each other.
➡️ Optimizing the pH Value
The very first and most important step in water treatment is adjusting the water's chemical reaction, which can be checked by measuring the pH level. This is measured on a scale from 0 to 14, where a value of 7 indicates a neutral state. Values below 7 indicate acidic, while values above 7 indicate alkaline reactions. In the case of swimming pools, a minimally alkaline range is ideal, as the pH value of the human eye is around 7.5, so values below 7.2 can irritate the eyes of swimmers. Furthermore, acidic water is corrosive, which damages the mechanical systems. A pH level above 7.8 should also be avoided, as it also causes eye irritation and, moreover, drastically reduces the efficiency of disinfectants.
From the perspective of pool water, the most optimal pH range is between 7.2 and 7.6, which can be calibrated using specific pH regulating (pH-minus or pH-plus) chemicals.
Pool owners frequently face the phenomenon that despite precisely dosed disinfectant, the water remains cloudy, opaque, or algae-infested. In the vast majority of cases, a pH value that is too high is behind the issue, which neutralizes the effect of chlorine.
➡️ Total Alkalinity (TA Value)
This indicator shows the stability of the water's pH value, meaning its buffering capacity against fluctuations. Its value can be measured with a digital or manual water analyzer tester. The ideal total alkalinity level falls between 80 and 120 mg/liter. If this value exceeds the optimal level, a negative spiral begins: the greater the deviation, the more pH reducers and disinfectants will be required, which ultimately leads to severe skin and eye irritation.
➡️ Controlling Water Hardness
Water hardness is determined by the concentration of dissolved calcium and magnesium salts in the water. If the water is too hard, excess salts precipitate in the form of a hard limescale layer in the pipelines, on the pool's internal liner, and inside the sand filter tank. By dosing suitable stabilizing chemicals, this process can be prevented, protecting expensive mechanical devices from malfunction.
2. Effective Water Disinfection:
Disinfectants are specific pool chemicals whose task is the complete destruction of harmful microorganisms (bacteria, algae spores, fungi, and viruses) appearing in the water. The proliferation of these organisms can cause infections, illnesses, and leads to rapid clouding of the water. The most widespread and reliable disinfection method is chlorine-based chemical treatment.
Free Active Chlorine Content (FC): The pool water must contain just enough free chlorine to guaranteed destroy pathogens, but without exerting any harmful effects on the health of swimmers. The recommended level is 0.6–1.0 mg/liter. For those sensitive to chlorine or for young children, chlorine-free active oxygen disinfection can provide a solution, but integrating a modern salt chlorinator (salt electrolysis), an ozone system, or an UV-lamp sterilizer equipment is also an excellent alternative.
3. Security Algae Prevention:
To prevent the settling and proliferation of algae, non-chlorine-based algaecide products, which are completely harmless from a human health perspective, can be applied. If the concentration of active chlorine and the specific algaecide pool chemical drops below the critical level, the water can turn completely green in as little as 12 hours. This process can be reversed in its initial phase by so-called shock chlorination, when the normal chlorine level is temporarily raised to 2-3 times its value. It is worth performing this shock treatment preventively every two weeks, and once a week in the case of water heated permanently above 26 °C.
4. Flocculation and Cleaning:
The sand filter alone is not always capable of retaining microscopic floating impurities in the water. Due to these tiny particles, the water becomes opaque and dull. The problem can be resolved by adding a flocculant (coagulant): the chemical groups the minute particles into larger flakes, so the sand or glass filter can then easily filter out the increased-size dirt clumps from the system.
➡️ Combined, Multi-functional Chemicals
To simplify daily water maintenance, complex, multi-component pool chemicals exist (e.g., multi-tablets) that contain an algaecide, a flocculant, a chlorine stabilizer, and limescale-preventing ingredients alongside the disinfectant base, thereby providing protection in a single step.
Our additional professional pool technology services and products:
- Pool liner installation – Precision installation of durable, UV-stable, and perfectly watertight reinforced membranes.
- Pool construction – Turnkey engineering design and structural execution of Porocell and shuttering block pools.
- Pool enclosure – A wide selection of high and low-profile, easily retractable polycarbonate structures.
- Pool shutter – Automated safety cover systems with thermally insulated slats floating on the water surface.
- Pool roller shutter – Aesthetic, recessed, or surface-mounted automated winding solutions.
- Pool renovation – Complex reconstruction of existing pool structures and outdated mechanical systems.
- Pool heat pump – Energy-saving, inverter heating systems for climate-independent swimming comfort.
