How Does Dechlorinator Work? Read This Before Using It

How does dechlorinator work? This is a question that many fish keepers have. 

In today’s article, we will share the facts about dechlorinator and respond to your commonly asked questions regarding how to use them, possible problems associated with overdosing, and what distinguishes the various dechlorinators.

Let’s delve into the bottom of it!

What Is Dechlorinator? 

Dechlorinator, also known as water conditioners, chlorine remover, or chlorine neutralizer, is the famous chemical additive that eliminates chlorine in your aquarium and creates safe water for your pet fish to breathe. Some dechlorinators also work on chloramine, which is produced by combining ammonia with chlorine.

chlorine remover

How Does Dechlorinator Work? 

The H10Na2O8S2 (active ingredient) has been found in several dechlorinators interacting with Cl2 – Chloride (in tap water which is a harmful factor for your fish) to create 2HCl, S, & Na2SO4. HCl, S, and even Na2SO4 are harmless for the aquarium, not affecting your fish.

Why Should You Use A Dechlorinator For Fish Systems?

Because chlorine is poisonous to all fish, which damages their gills severely and causes asphyxiation & death. In the meantime, the water source most fishkeepers use is tap water with chlorine included. Your city water has chloramine and chlorine to destroy hazardous germs and sanitize the water to make it suitable for human consumption, so it is hard to find non-chlorine sources.

Chlorine in greater amounts is thought to be lethal for fish. Even in low quantities, it can harm the gills of your fish, causing stress. More importantly, the poisoning of fish by chlorine has no proven cure. If they’re found out, they’ll probably die. Always keep your eyes on the water in the tank, and water conditioners are required.

If you use bottled water or well water, normally, you don’t have to use water conditioners. Still, the water from the bottle is more likely to lack the buffers or minerals that your fish yearn for. That is what you should be concerned about.

Just because you have never had any problems with water without a dechlorinator, it does not mean your water is 100% safe for your pet. Turning to a popular product that works for many fish keepers does not harm.

Fish in Aquarium

How To Use A Dechlorinator? 

The dose guidelines for each dechlorinator vary significantly, so aquarists must consult the label of the specific dechlorinator they bought. However, the dose of the most effective dechlorinators is around one drop for every eight liters or 1 drop for every two liters of water.

But keep in mind that you only have to treat the additional water, not the whole tank, except if it is the 1st time you pour water into an empty tank.

Dechlorinators often function extremely quickly, mostly eliminating the chlorine in 1 or 2 mins. Chloramine will need more time, like 5 mins, to remove. Don’t forget to read and carefully follow the instructions. These guides will explain how much dechlorinator to use and how long you must wait until it finishes its job.

Is Dechlorinator Harmful to Fish?

Most of the time, no. Nevertheless, there are a few exceptional, one-off instances in which it may be unsafe. When chlorine is taken out of the water by the dechlorinator-reducing agents, oxygen is used up, and then this reaction might be dangerous in tanks with insufficient oxygen. 

However, as long as you know of it, you can handle it easily by providing more oxygen to your pet. It is rare, but always being prepared is the secret to success.

Dechlorinator Types 

Dechlorinators come in two different forms: granular & liquid.

Granular Dechlorinator

Before pouring the city water into your tank, add granulated dechlorinators. The ammonia is then gradually released into the system as time passes. They may also be utilized in hot tubs, ponds, and other water bodies.

Liquid Dechlorinator

To get rid of chlorine from the water before it gets into the aquarium, use a liquid dechlorinator, which is the kind that goes in a jar or bottle and can be poured right into the tank. It contains an ammonia-based liquid, although chloramines don’t react as effectively.


Is It Possible To Dechlorinate Water That Contains Fish?

Yes. Using a dechlorinator from a famous and trustworthy brand right into your aquarium is safe before introducing new water. The majority of dechlorinators may be increased up to five times the recommended dosage, even in the presence of critters in the aquarium.

Is It Possible To Over-dechlorinate Aquariums?

Yes. If you accidentally use too much of the recommended dose, there is a good chance that your fish will not be harmed. However, to be 100% sure, consult manufacturers and your pet expert!

beautiful aquarium

How Soon Can You Introduce Fish After Using Dechlorinator?

It depends on your tank’s size, its condition, and the water you are about to add or change. 

When used appropriately, dechlorinators are usually benign to fish. You do not need to wait to introduce fish after applying the water conditioner, especially if you’re just changing a small amount of water. Still, when you are about to change the whole tank, it’s best to let the fish out and apply water conditioners to ensure your pet’s safety. You should wait a few minutes to let the dechlorinator take effect, and then you put your fish back in. 

Waiting no more than two to five minutes before introducing fish is sufficient for tanks with appropriate water flow or when a water pump is inactive to distribute the dechlorinator throughout the whole tank evenly.

Nevertheless, the procedure may require some time if the tank water is still and not adequately circulating. So you might need to separate the fish and pause for roughly 30 mins to let the water conditioners work effectively should your aquarium be larger & not have adequate circulation.


Now you get the answer to your query of how dechlorinator work. Always treat the new water you are about to add to ensure your fish’s living environment. You never want to accidentally harm them because you forget to remove chlorine or chloramine from the tap water. 

The dechlorinator just works in the way of a chemical reaction that makes the water a good environment for your pets to breathe while excluding the harmful chemicals. The amount you have to invest in a dechlorinator is not too big that everyone can afford.