"Pool shock" is a chemical treatment used in swimming pool maintenance to quickly increase the oxygenation or disinfection capacity of the water to eliminate pollutants, bacteria, algae, or chloramines (compounds that cause chlorine odor). Depending on the chemical used, there are two main types of pool shock: chlorine shock and non-chlorine shock :
Chlorine Shock
- Use high concentrations of chlorine (such as sodium hypochlorite, sodium dichloroisocyanurate, etc.) for strong disinfection and oxidation.
- It is mainly used to kill stubborn algae and bacteria and decompose organic pollutants (such as sweat, urine, etc.).
- It is usually necessary to wait several hours (or even a day) before a treated pool is safe to swim in to avoid irritation to the skin and eyes from high chlorine concentrations.
Non-Chlorine Shock
- Use an oxidizing agent such as potassium persulfate (MPS) to break down pollutants through oxidation without increasing chlorine levels.
- Suitable for quickly treating slightly turbid water or eliminating chloramines (reducing chlorine odor).
- Swimmers usually only need to wait 15-30 minutes before re-entering the water, which is gentler on the skin and eyes.
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Main functions:
- Oxidize organic matter : decompose pollutants such as sweat and oil.
- Chloramine Eliminator : Reduces chlorine odor and irritation.
- Restore chlorine activity : Improve the disinfection efficiency of free chlorine by reducing bound chlorine.
- Emergency treatment : Rapid water purification after heavy rain or when swimming pool usage surges.
When is Shock needed?
- The water is turbid or there is algae growth.
- There is a noticeable chlorine odor (excessive chloramines).
- Free chlorine levels remain low.
- After heavy use or in extreme weather (such as high temperature, heavy rain).
Notes:
- Chlorine shock must be used strictly according to dosage to avoid corrosion of equipment or irritation to the human body.
- Non-chlorine shock cannot replace chlorine-based products for treating severe algae problems.
- It is recommended to use water quality testing tools (such as test strips or digital detectors) to determine whether shock treatment is required.