In the process of swimming pool management, we often encounter a series of questions from customers: “How should these disinfection tablets be used? What is the dosage? How is it calculated?” Some customers also report that the effect of the chemicals is not satisfactory or even non-existent. To address these concerns, we conducted a comprehensive summary today, aiming to provide guidance to the vast pool managers. Through an in-depth overview of these issues, we can better grasp the process of medication to ensure effective control of water quality.
I. Algae Suppression and Inhibition
In the process of inhibiting algae, copper sulfate is a commonly used chemical. Under normal circumstances, the recommended preventive dosage for copper sulfate is 2-3 kg per 1000 cubic meters of water, and it is generally performed twice (note that subsequent steps can only be taken 2 hours after chemical dosage).
However, with an increase in the number of swimmers, organic pollution may increase, and rainy days can lead to changes in water quality, promoting algae growth. In such cases, it is necessary to add copper sulfate again. Additionally, if dealing with new water, double the dosage should be considered.
When applying algaecides, it is usually recommended to use 1 bottle per 1000 cubic meters of water for preventive purposes, with monthly applications of 1-2 times. If the water has already turned green due to algae growth, the dosage needs to be doubled.
This dosing strategy can effectively control algae growth, maintain water cleanliness, and ensure the safety and health of the swimming pool. When adding chemicals, it is essential to follow the correct dosage and frequency to achieve the best anti-algae effect.
II. Measurement of Disinfectant Dosage for Pool Disinfection
- Choosing Disinfectants:
Swimming pool water disinfection typically uses disinfection chlorine tablets or trichloroisocyanuric acid disinfection powder. The recommended method is to split the dosage into two, once after the pool is closed for the day and another 1-2 hours before opening.
- Timing of Dosage:
Splitting the dosage is intended to maintain long-lasting disinfection effects. Adding disinfectant after the pool is closed at night takes advantage of lower temperatures and no sunlight, helping to extend the efficacy of the disinfectant. The second dosage is performed 1-2 hours before opening to ensure that the residual chlorine in the water meets sanitary requirements.
- Volatility Characteristics:
All chlorine-containing disinfectants are volatile, and the rate of volatility is directly related to sunlight and temperature. In sunny and hot weather, disinfectants are more likely to evaporate.
- Relationship Between Volatility and Timing of Dosage:
Adding disinfectant after closing for the day takes advantage of the lower nighttime temperatures and absence of sunlight, helping to prolong the efficacy of the disinfectant. Adding disinfectant too early may result in rapid evaporation before opening, leading to insufficient residual chlorine at the start of the day.
- Chlorine Residual Monitoring and Adjustment:
Chlorine residual testing can be performed 1-2 hours before opening to ensure that the residual chlorine meets sanitary requirements. If the residual chlorine is too low, a moderate amount of disinfectant can be added to maintain water hygiene. By following a reasonable dosage schedule and monitoring chlorine residuals, the disinfection effect of trichloroisocyanuric acid can be more thorough and effective. Such operational strategies help maintain the cleanliness and hygiene of the swimming pool water, providing a safe and healthy swimming environment for swimmers.
III. Use of Chlorine Tablets in Pools
- Characteristics of Disinfection Tablets:
Chlorine content is approximately ≥50%, belonging to a soluble tablet that dissolves completely in about 10 minutes after being added to the swimming pool. Recommended Dosage:
To ensure that the pool’s residual chlorine meets standards and effectively maintains water quality, it is recommended to add 2-4 grams of disinfection tablets per cubic meter of water (equivalent to 2-4 kg per 1000 cubic meters).
- Chlorine Calculation Formula:
Taking the example of adding 2 grams of a tablet with 50% chlorine to 1 cubic meter, the formula for calculating residual chlorine is: 2g × 50% × 1000 = 1000mg (effective chlorine content in 2 grams of disinfection tablet, unit: grams). Residual chlorine concentration calculation: 1000mg + 1000L (1 cubic meter) = 1mg/L (equivalent to 1 ppm).
- Relationship Between Disinfection Effect and Water Quality:
After adding disinfectant, its effect interacts with bacteria and algae in the water, while also being affected by the consumption of organic matter in the water. Different swimming pools, due to varying water quality conditions, will have different measurable residual chlorine concentrations after adding the same amount of disinfectant.
- Dosing Recommendations:
When applying chemicals in the evening, it is recommended to add a minimum of 2 kg per 1000 cubic meters to ensure the disinfection effect. If the water quality has turned green or cloudy, it is preferable to double the dosage.
- Pre-opening Dosage:
It is advisable to add disinfection tablets 0.5-1 hour before the swimming pool opens. Before adding, test the residual chlorine, and calculate the dosage based on adding 2 kg of disinfection tablets per 1000 cubic meters to increase by 1mg/L. For example, for a 500 cubic meter pool requiring an increase of 0.5mg/L, 0.5 kg of disinfection tablets should be added.
Using chemicals in the pool correctly and controlling the dosage appropriately are crucial steps in maintaining water cleanliness and swimmer health. The use of medication methods should be adjusted based on the specific situation of the pool and water quality monitoring results to achieve optimal results. Through scientific management and regular testing, we can ensure the stability of pool water quality, providing a refreshing and healthy swimming environment for swimmers.
