How to Remove Chlorine from Water

If you're concerned about chlorine in tap water, whether it's for drinking, aquarium use, or gardening, there are many quick and easy ways to eliminate it. Natural methods such as boiling or letting the water evaporate can be helpful for small quantities. However, for larger amounts, you'll need to use chlorine-removing chemicals. In any case, investing in a water filtration system to remove chlorine at the source can save you time in the long run.

Install a spray nozzle for your fish tank. If you're treating water in a pond, you can use a sprayer (like one attached to a water hose) to introduce air into the water as it flows into the tank. Chlorine is a volatile substance and will naturally dissipate in an open water tank, but the spray nozzle will speed up this process significantly.

• However, a spray nozzle will not eliminate chloramine, a less volatile substance used by many water utilities. You'll need additional chlorine-removing chemicals for that.

Use additional chlorine-removing chemicals to eliminate both chlorine and chloramine. You can purchase chlorine removers at pet stores specializing in aquarium supplies. Each chlorine remover specifies the amount of water it can treat, so be sure to follow the instructions carefully. Simply open the bottle, tip it, and pour out the appropriate amount of chemical to remove chlorine.

• The water treated with chlorine remover is safe to use immediately.
• If your aquarium has a biological filter, choose a chlorine remover that does not contain ammonia-neutralizing chemicals to avoid harming the filter.

Use an air pump for your aquarium. Always treat the water for chlorine before introducing fish into the tank, but aerating the water also helps remove chlorine. Aquariums typically require an air pump to maintain water circulation, making this a convenient two-in-one solution.

• Choose the appropriate pump based on the tank type, size, and the kind of aquatic animals in your care.

Use a charcoal filter to treat drinking water. Activated carbon is a specialized filtering material that removes chlorine, chloramine, and organic compounds from water. Some activated carbon filters can be installed directly into your home's water supply. Alternatively, you can purchase a portable filtering pitcher that uses activated carbon.

• Activated carbon filters will remove both chlorine and chloramine.
• Choose an activated carbon filter that meets NSF International standards, a non-profit organization that tests and certifies water filtration products.

Install a reverse osmosis filter in your home. Reverse osmosis is a process that removes ions and suspended particles from water. A reverse osmosis system can be installed directly under the kitchen sink, where your water supply enters the house, making it more convenient than other chlorine-removal methods. However, this system is quite expensive, with costs potentially reaching tens of millions of VND.

• Additionally, reverse osmosis filters use a lot of energy and can waste water.

Replace the filter when necessary. Every filter eventually needs to be replaced. The time between filter replacements will depend on the filter size and how frequently it’s used. Be sure to check the manufacturer's guide to ensure you're replacing the filter on time.

Boil chlorinated water for 20 minutes. The boiling process generates heat and aerates the water (through bubbles), and this combination is sufficient to remove chlorine after 20 minutes. However, this method is not practical if you need to treat a large quantity of water.

• Boiling water for at least 20 minutes will also help remove chloramine, which some areas use in place of chlorine.

Allow chlorine to naturally evaporate. Fill a bucket or basin with the water that needs to be treated. Place the container in a clean area with minimal dust so the water remains uncontaminated. Chlorine in the water will gradually dissipate through exposure to sunlight and air.

• The time needed for chlorine removal with this method depends on the amount of chlorine you wish to remove and the amount of direct sunlight the water receives. Additionally, the wider and shallower the container, the faster the chlorine will evaporate.
• Check periodically with a chlorine test kit to monitor the chlorine levels in the water.
• This evaporation method will not remove chloramine, which some water utilities use instead of chlorine. It is also not recommended for drinking water treatment, as it can easily become contaminated.

Dissolve 1 teaspoon of ascorbic acid for every 4 liters of water. Ascorbic acid powder (also known as vitamin C) neutralizes chlorine. Simply sprinkle the ascorbic acid into the water and stir it. This method is most effective when treating water for gardening or hydroponic systems.

• Ascorbic acid is quite inexpensive and can be purchased at aquarium supply stores.
• Ascorbic acid can neutralize both chlorine and chloramine. It also has minimal impact on the taste of water, making it a viable option for treating drinking water.

Use ultraviolet (UV) light to remove chlorine from water. Position the water that needs chlorine removal as close to the UV source as possible. The amount of UV radiation required to remove chlorine depends on the volume of water, the intensity of the UV light, and the presence of organic chemicals in the water.

• Typically, water should be treated with UV light at a wavelength of 254 nm, with a radiation energy density of 600 mJ per cm².
• UV light will eliminate both chloramine and chlorine. This method is also suitable for treating drinking water.