Last Updated on January 1, 2023
Swimming pools are primarily used for entertainment. They can also be used for exercise, therapy, and relaxation. When the water in pools is contaminated it makes them dangerous and can cause diseases like dermatitis, eye irritation, or even respiratory illness. Swimming pool disinfection happens either with an oxidizing chemical (chlorine), a reducing chemical (sodium hypochlorite), or by exposing the water to ultraviolet light.
What Chemicals Used in Swimming Pools?
These chemicals are used for sanitizing/disinfecting the water in pools. Chlorine is a strong oxidant and is often used in swimming pools to disinfect them. This strong oxidant can irritate the eyes, skin, and respiratory system. Furthermore, it leaves behind a strong chemical smell which has caused some amount of concern in the past.
- Alum – Alum uses aluminum and potassium sulfate to increase water clarity and reduce chemical use by preventing bleaching and corrosion. Although alum is a reducing agent, it does not leave harmful residues behind which makes it safe for human contact. It is also known to be an effective algaecide.
- Uric acid – Uric acid is a compound found in urine. It is often used as a way of reducing the amount of chlorine needed to keep pools clean and sanitary. Since uric acid can come from anywhere, it is considered to be pretty safe for humans and only causes irritation if enough gets into people’s eyes or on their skin.
- Calcium hypochlorite – Calcium hypochlorite is a strong oxidant as well. It is typically used to treat small areas of the water and reduce the amount of chlorine needed to sanitize larger areas.
- Borax Decahydrate – Borax Decahydrate, or sodium tetraborate decahydrate, is a compound that uses borates and carbonates to prevent corrosion and bleaching in swimming pools. It also reduces combined chlorine levels within the water, which also reduces the amount of chlorine needed to keep pool water clean.
- Alkalinity adjuster – Sodium bicarbonate (baking soda) can be added to the pool to increase your total alkalinity and overall water pH.
- Cyanuric acid – This compound stabilizes chlorine by preventing sunlight from decreasing the effectiveness of the disinfectant through oxidation. It is often used in conjunction with chlorine to ensure that it doesn’t break down as quickly as it would otherwise.
- Calcium chloride – If calcium levels within the pool are too low, this chemical can be added to increase them and harden the water. This can prevent problems like cloudy water and scaling.
- Chlorine stabilizer – Chlorine stabilizer is another chemical that can be used in conjunction with chlorine to prevent sunlight from breaking it down. This chemical is often used when you are using calcium hypochlorite or calcium monosulfate to get the most out of your pool sanitizer.
- Guanidine HCL – Also known as glycin, this compound is typically added to pools where the water is very alkaline, and there isn’t enough chlorine in the water. This chemical binds with the bicarbonates to create a more neutral pH.
- Metabolites – Amine surfactants like cocamide and methyl di-ethanol amine (MEA) can be added to pools to reduce the number of algaecides needed to keep them clean. They also break down chloramines which stop surfaces from appearing slippery when exposed to water.
- PEG-400 – Also known as polyethylene glycol, this chemical is typically used to clean metal surfaces within the pool. It breaks down chloramines and algaecides which prevents surfaces from appearing slippery when exposed to water.
- Alkyl amido propyl dimethylamine lactate – This compound removes calcium deposits and prevents scaling within the pool. It is often used in conjunction with other chemicals to remove calcium deposits, scale, or make water appear cloudy when it shouldn’t be.
- Potassium hydroxide – When the pH levels of your pool are too low, this chemical can be added to increase the pH. This prevents scaling and cloudy water within the pool.
- Guanidine carbonate – If calcium levels within your pool are too high, this chemical can be added to reduce them and soften the water. It is often used in conjunction with other chemicals because it can also cause cloudy water.
- Sodium bicarbonate – If the pH levels of your pool are too low, this chemical can be added to increase them and harden the water. It is often used in conjunction with other chemicals to prevent scaling within the pool.
Acid should never be added directly to water because it could cause the pH to crash, which will make the water unsafe for swimming. Instead, it is typically stored in a separate compartment and then slowly dripped into the pool over time. When performing this procedure, you must be careful not to add too much acid to the pool. This can cause a drop in pH and make the water unsafe for swimming. Alternatively, if you add too little acid, this will make your pool water more alkaline. This is also bad because it can result in scaling and cloudy water.