Pool Disinfection is an indispensable maintenance step for a swimming pool. Chlorine is the most widely used type of pool disinfectant worldwide. It helps eliminate bacteria and viruses in the swimming pool and inhibits the growth of algae. When you start owning a swimming pool and are maintaining it, you might wonder, "Can I just put chlorine disinfectant directly into the pool?" The answer is no. This article will provide you with a detailed elaboration on relevant content, such as the correct methods, safety precautions, and usage guidelines for adding chlorine disinfectants to swimming pools.
Understand the forms and types of chlorine disinfectants
The chlorine disinfectants commonly used in swimming pools come in the following forms, each with its own distinct characteristics:
Granular chlorine: Sodium dichloroisocyanurate, calcium hypochlorite
Sodium dichloroisocyanurate (SDIC, NaDCC) : The effective chlorine content is usually 55%, 56%, or 60%. It contains cyanuric acid and has strong stability. It dissolves quickly.
Calcium hypochlorite (CHC) : The effective chlorine content is usually 65-70%. It dissolves quickly, but there will be insoluble substances.
These two are highly suitable for pool impact therapy and can rapidly increase the chlorine content.
Chlorine Tablets: Trichloroisocyanuric Acid
Trichloroisocyanuric acid (TCCA) : The effective chlorine content is usually 90% per minute. When it is made into multifunctional tablets, the effective chlorine content is slightly lower. Tablets are commonly available in 20G and 200g.
It contains cyanuric acid and has strong stability.
It dissolves slowly and can maintain a stable chlorine content for a long time.
Suitable for daily disinfection of swimming pools.
Liquid chlorine: Sodium hypochlorite
Sodium hypochlorite: A very traditional disinfectant. The effective chlorine content is usually 10-15%, which is relatively low. Unstable, effective chlorine is prone to loss.
Each chlorine disinfectant has its own advantages and limitations. When maintaining a swimming pool, it is necessary to fully understand and determine which type of chlorine is more suitable at present.
How to add chlorine disinfectant to a swimming pool?
Granular chlorine
Chlorine disinfectant is a strong oxidant. It is not recommended to directly add undissolved granular chlorine.
Direct addition may cause local bleaching or damage to the swimming pool.
Local high chlorine concentration can irritate the skin and eyes.
Best Practice
Dissolve SDIC particles in a bucket of water in advance and then evenly distribute them around the swimming pool.
Add water first and then chlorine to prevent a chemical reaction.
Stir until completely dissolved and ensure even distribution.
Note: Calcium hypochlorite will form a precipitate after dissolution. The supernatant should be used after the precipitate has settled.
Chlorine tablets (trichloroisocyanuric acid tablets)
It is usually added through floating dispensers, feeders or skimmers. These devices can control the slow release of chlorine, minimize the risk of concentrated "hotspots", and prevent damage to the pool surface or irritation to swimmers.
Important Notice
Never place the pills directly at the bottom of the swimming pool or on the steps.
Avoid adding too many tablets at one time to prevent the local chlorine concentration from being too high.
Regularly check the chlorine content to ensure proper disinfection.
Liquid chlorine
Liquid chlorine can usually be safely poured directly into swimming pool water. However, it should be added in the following circumstances:
Slowly return to the area near the pool to help with the distribution.
Start the pump to circulate the water and mix it.
Closely monitor the free chlorine content and pH value to prevent excessive chlorination.
Safety precautions when adding chlorine
If safety rules are followed, adding chlorine to the swimming pool is very simple:
Wear protective equipment
Gloves and goggles can prevent the skin and eyes from being irritated.
Avoid inhaling the smoke of concentrated chlorine gas.
Never mix different types of chlorine
Mixing different types of chlorine (such as liquid and granular) can cause dangerous chemical reactions.
Always store chemicals separately and use them as per the instructions.
Avoid direct contact with the pool surface
Granular chlorine or chlorine tablets must never come into direct contact with the pool walls, floors or linings.
Use a dispenser, feeder or pre-dissolve in water.
Measure and test water levels
Ideal free chlorine: usually 1-3 ppm.
Regularly test the pH value; Optimal range: 7.2-7.8.
Adjust the alkalinity and stabilizer (cyanuric acid) to maintain the chlorine efficiency.
Frequently Asked Questions (FAQ) About Pool
A: Can I add chlorine tablets directly to the pool?
Q: No. Chlorine tablets (such as TCCA) should not be placed directly on the pool floor or steps. Use a floating dispenser, feeder, or skimmer basket to ensure slow, even release and to prevent surface damage or irritation to swimmers.
A: Can I pour granular chlorine straight into the pool water?
Q: It is not recommended. Granular chlorine, such as SDIC or calcium hypochlorite, should be pre-dissolved in a bucket of water before adding to the pool. This prevents hot spots, bleaching, or surface damage.
A: Is it safe to pour liquid chlorine directly into the pool?
Q: Yes, liquid chlorine (sodium hypochlorite) can be added directly, but it should be poured slowly near a return jet with the pump running to ensure even distribution and proper circulation.
A: Why does the pool water become cloudy after adding granular chlorine?
Q: Certain granular chlorines, like calcium hypochlorite, may contain insoluble particles. If added directly without dissolving, these particles can remain suspended, causing cloudy or hazy water. Pre-dissolving helps maintain clarity.
A: Can I mix different types of chlorine together?
Q: No. Mixing different forms of chlorine (e.g., liquid and granular) can trigger dangerous chemical reactions. Always use one type at a time and follow safe handling instructions.
A: What safety equipment should I use when handling chlorine?
Q: Always wear gloves, goggles, and protective clothing. Avoid inhaling chlorine fumes and ensure proper ventilation during handling.
Adding chlorine disinfectants directly into your swimming pool may seem convenient, but it often leads to uneven chlorine distribution, pool surface damage, and potential health risks for swimmers. Each chlorine form—granular, tablet, or liquid—has its own application method, and following the correct procedure is essential for safe and effective pool maintenance.
Post time: Sep-19-2025