If you are a fish lover and planning to build an aquarium, there are few things you should consider first. Water is definitely one of them. Regardless of the aquarium type (freshwater or saline water), you must use chlorine-free water. Otherwise, your fish have to face many problems. The high chlorine level can cause a high mortality rate in fish.
So How Long Does Water Take to Dechlorinate? It will take 1 to 5 days or 24 to 120 hours to completely dechlorinate the water if it sits in the tank. In municipal water chlorine level of 1.5 to 2.0 ppm but it can change. So We cannot tell an exact period because it depends on initial chlorin concentration in water, water temperature, water volume, chemical properties of water, and tank filter type. Also, keep in mind 0.1-0.3 ppm chlorine levels are lethal to most fish.
So it is essential to remove Chlorine from the water before introducing fish into the aquarium. Chlorin can remove from water using different methods. Now in this article, we are going to discuss some techniques to remove Chlorine from water.
Table : How Long Does Water Take to Dechlorinate
How to dechlorinate the tap water?
Natural methods (how to remove Chlorine from tap water naturally)
Keep in a storage tank
We are going to talk about the easiest and inexpensive method first. It is to keep water in a storage tank to remove Chlorine. Although this process is affordable, the process takes a long time.
How long does it take for Chlorine to evaporate from water for fish? The time of storage can be varied from 1 to 5 days. The storing time depends on chlorine concentration in the water. For example, if the chlorine concentration is 2 ppm (parts per million), you have to keep that water for at least 110 hr. to remove Chlorine in the water.
But there is an important point you should keep in mind. It is documented that Chloramine can not remove only with evaporation. To remove Chloramine, you have to heat the water or other methods.
What is Chloramine?
Chloramine is a chemical that forms in the water when Chlorine reacts with ammonia in water. Chloramine is also toxic to fish. Most of the time, it is available in tab water due to chlorine usage in water disinfection. Sometimes Chloramine is directly added to the water of highly populated areas because it is a more efficient disinfectant. It is deadly to fish because it can absorb through fish skin and destroy cells.
Chloramine vs Chlorine
Chloramine and Chlorine may sound like the same thing, But they are different from each other. It is a variant of Chlorine that has ammonia in it. Chloramine stays in water active than Chlorine. But Chloramine is toxic to fish with comparing with Chlorine.
How long does it take for Chlorine to evaporate from 1 gallon of tap water
it takes 1 to 2 hours to dechlorinate the water, but it will not remove Chloramine from water. It can take up to 4 days. But you can dechlorinate and remove Chloramine quickly if you use dechlorinator. If you boil 1 gallon of water, it can take up to 8 minutes to dechlorinate.
Boiling the water for Dechlorinate
As I mentioned earlier, evaporation only removes Chlorine from the water. Chloramine, a chemical by-product of Chlorine, did not evaporate as easy as Chlorine. It remains in the tank. To remove this Chloramine, you need to boil the water. Boiling will remove it faster than Chlorine.
It is also believe boiling will produce enough kinetic energy to remove Chlorine from the water effectively. Boiling will reduce the holding capacity of dissolved gases in water.
Boiling 10 gallons of water for about 8 minutes will eliminate 1ppm of Chlorine from the water. Chloramine is a stable chemical than Chlorine. Therefore it will take much more time to evaporate from the system. It will take around 1 hr to remove Chloramine from the same volume of water
This method is not suitable for a large amount of water. If you have a large aquarium and need a lot of Dechlorination, you should partially do one batch.
Remove Chlorine by Aeration
An air pump will help you to dechlorinate the water. When water aerated through the air pump, it removes Chlorine mechanically. The aeration created by the pump helps to remove Chlorine In the water.
An air pump will not be an extra burden for you since aeration is needed to keep the water circulate. The size of the aeration pump will depend on the aquarium size. If you have a bigger tank with a large amount of water, you need a heavy-duty air pump.
How long does it take to dechlorinate water with an air pump
It takes 12 to 24 hours under normal conditions, but it depends on the water condition and chlorine concentration in the water. The air pump or aeration can indeed accelerate the dechlorinate process because it increases water circulation.
Ultraviolet light to dechlorinate
This is an expensive method to remove Chlorine from your aquarium water. You have to purchase a UV light for this method
The amount of light needed for Dechlorination depends on your aquarium’s size (amount of water). The large aquarium needs a significant UV light source. The length of the Dechlorination relies on the level of organic matter in the water.
Is Ultraviolet light remove Chlorine?
Yes, it can. UV light dechlorinates tap water by attacking chlorine molecules with ultraviolet rays. The UV light will remove both Chlorine and Chloramine from tap water when correctly set up. They also have the added advantage of handling and making tap water straightforward and safe to fish.
If you are using UV light dechlorination, make sure it can emit 254 nm wavelength and a density (radiant) of 600 ml because it can remove chemicals.
Chemical method to dechlorinate the water
Use water softener
A water softener will not work well without a filter. If you only use softener, it only removes magnesium, iron, and calcium. You should use a recommended filter to eliminate Chlorine from your aquarium. But some water softeners claims to remove Chlorine from water by mixing water softener resins with Granulated Activated Carbon (GAC). The problem is Granulated Activated Carbon (GAC) only removes Chlorine for 1 to 2 years. But softener resins will last for 10 years. The filter will stop removing Chlorine in 2 years while filter lasing 10 years. It is better to use the activated carbon filter separately.
Another recommended excellent chlorine removal is the KDF-55 filter media, which is granular and can remove large amounts of Chlorine. For better performance, you should place the filter inside a media guard. Chlorine-free water will come out of the filter. It uses redox reactions to remove Chlorine from water. It is common to use KDF-55 with an activated carbon filter because it can extent activated carbon lifetime by 90%.
Does Water Softener Remove Chlorine?
Some water softeners mixed with activated Carbon or KFG 55 remove Chlorine from water, but Water Softener resins in self dose do not remove Chlorine from water. So make it contains activated Carbon.
Does Carbon filter Remove Chlorine
Your carbon filter will use adsorption to remove harmful material in the water carbon filter consisting of porous material and toxic substances trapped in these pores. A carbon filter commonly uses to clean drinking water. We can use carbon filters to purify aquarium water, especially chlorinated water. It is also essential to remove Chloramine from the water.
If you use your home water supply to fill the aquarium and already have a carbon filter, you do not have to worry about chlorination. But if you do not have a carbon filter stored, you should consider buying one before introducing fish.
You can easily buy activated carbon filter from a shop. Make sure the one you buy is with suitable quality materials. You should monitor the pH value of the water after every filter process.
Does Ascorbic acid /vitamin c Remove Chlorine?
Vitamin C is the safest chemical method for neutralizing Chlorine, and Chloramine only takes a few moments. It is also known as water-soluble Ascorbic acid, or Vitamin C. we can also use sodium ascorbate.
Vitamin C is not harmful to organisms at the amounts used for dechlorinating water. At the same time, ascorbic acid is slightly acidic and lowers the treated water’s pH in large doses. But sodium ascorbate is neutral. So It does not affect the pH of the treated water. If stored in a cool, dark spot, both types are stable, with a shelf life of 1 year in dry form.
However, once it is mixed into solution, vitamin C degrades in a day or two. So it is not ideal to use a pre-mixed vitamin C solution. Also, Vitamin C will not reduce dissolved oxygen in the water as sodium thiosulphate which is an anther chemical use to Remove Chlorine
Ascorbic acid + Hypochlorous acid → Dehydroascorbic acid + Hydrochloric acid + water
What is the Dosage if vitamin c to remove Chlorine?
Per 100 gallons of water, you need to add 1 gram of ascorbic acid to neutralize 1 milligram per litre of Chlorine. This reaction is very rapid.
In other words, the neutralization of 1 part of Chlorine needs approximately 2.5 parts of ascorbic acid. Since ascorbic acid is weakly acidic, the pH of the water treated can decrease slightly.
How to use if vitamin c to remove Chlorine?
To neutralize Chlorine, sprinkle ascorbic acid on the water’s surface and stir for a few minutes. Chlorine will not dissolve in water. The chlorin precipitation will deposit at the bottom of the tank. This method is straightforward to use and less expensive. You can find ascorbic acid in any pet store.
Both chlorine products (Chlorine and Chloramine) will remove from this method. Since this reaction did not reduce dissolve oxygen in the tank. It is also beneficial for aquarium fish and plants.
Dechlorination water conditioner
Water conditioners are chemical formulations that use to condition the tap water before adding to an aquarium. A simple conditioner can contain dechlorinators. These products can remove Chlorine from your tank in a very short period. You can buy these products in many aquarium and online stores.
How to use Dechlorination Conditioner ?
Each dechlorinator is slightly different in the dosage recommendations, so you need to refer to the label on the dechlorinator you have purchased. However, most decent dechlorinators are dosed between one drop for every two gallons of water and two drops for each gallon of water. It is simple as that.
How Long Does Water Conditioner Take To Work?
As soon as they come into contact with the chlorine and chloramine molecules, it breaks them down. However, if the water is not circulating, this may take some time.
But to be safe, it is recommended to mix Dechlorinatior or Conditioner with water and aerate it for 30 minutes allowing water to circulate. That ensures all the Chlorine is neutralized. This enables the dechlorinator to remove chlorine molecules by coming into contact. Now the water should be safe to add to the aquarium.
Can I use a dechlorinator when the new water is already in the tank?
You just need to treat the new tap water you are adding to the tank; you do not need to treat the entire tank volume unless you are filling the tank for the first time.
Is dechlorinator/ Conditioner safe for fish?
Ideally, no. They should not affect the chemistry of water and should not involve other additives that you use. The more “extra things” your dechlorinator does, however the more likely some problem could occur. Also in small tanks without a filter, it can leave a residuer. But it depends on the type of dechlorinator/ Conditioner used. Carefully follow package directions and always clean and maintain filters.
You can use sodium thiosulfate to make your own Homemade dechlorinator. It is way cheap that once you buy from the shops. sodium thiosulfate is the easiest and most efficient way to extract Chlorine and Chloramine from your water. Both of them contain ssodium thiosulfate, which reacts to form harmless chloride ions with Chlorine (or the chlorine part of the Chloramine).
A range of approximately 2 to 7 parts of sodium thiosulfate is usually proposed to neutralize one part of Chlorine, such as neutralizing 1 litre of a 200 ppm chlorine solution, requiring approximately 0.4 to 1.4 grams of sodium thiosulfate to neutralizing one gallon of a 200 ppm chlorine solution,
There are many other types of homemade dechlorinators, but we are not sure about usability because most of them are not correctly tested. It is better to stick with traditional, well-known methods to be on the safe side.
How to know if the water is dechlorinated
Chlorine test kit
No matter what method you use to remove Chlorine from the water, you should have a chlorine test kit to test the water’s chlorine level. In that way, you can try the variation of chlorine level by using the test kit. The time you have to spend in Dechlorination is depended on the chlorine concentration in the water.
Once you select the dechlorination process, you can start Dechlorination. After the process, you can check the water by using the chlorine test kit. If the chlorine level is lower, you can move to the next step of building an aquarium. But if the chlorine level is still high, you have to go for another dechlorination process.
It is essential to remove not only Chlorine but also Chloramine from your water. Otherwise, fish will be negatively affected by harmful chemicals. So it is necessary to check both chlorine and chloramine levels in the water.
Introducing fish after Dechlorination
You can introduce fish in the dechlorinated water after checking Chlorine and chloramine level. But monitoring fish behaviour is essential at least for 2 hours. If fish behave strangely immediately, remove fish from the tank and check for the water’s pH level. Sometimes Dechlorination can cause a low pH level. But this happens very seldom.
How do I see if my fish are suffering from too much chlorine/Chlormine in the water?
Chlorine affected fish may look pale, appear to be coated in mucus, and grow red areas on their bodies. Affected fish can swim erratically or hover, gasping for breath at the top of the tank.
Other frequently asked questions
How long does it take to dechlorinate water in the sun?
It takes 24 hours under normal conditions, but it depends on the water condition and chlorine concentration in the water. The air pump or aeration can indeed accelerate the dechlorinate process because it increases water circulation.
How long does it take to dechlorinate water with an airstone
Under normal conditions, It takes 12 to 24 hours. The air pump or aeration can indeed accelerate the dechlorinate process because it increases water circulation.
how long can fish survive in chlorine water
The answer is Immediate. The fish gills are very susceptible to Chlorine so they will not survive in chlorine water. But in lower concentrations in Chlorine, they can live for a few minutes to a few hours. The chlorine levels between 0.1-0.3 ppm are toxic to fish. But in municipal water chlorine level of 1.5 to 2.0 ppm so fish will not survive in it.
If my tap water is already safe to use in my tank, do I still have to dechlorinate?
Before adding fish to the tank, you need to check the chlorine level of the water with the test kit. That will indicate if it is safe or not.
How to make tap water safe for fish without a conditioner.
Yes, it is possible. You can use chemical-free methods such as UV filter but it should correctly used if you can aerate the water for 1 to 5 days it can work too. But chemical a cheep and less time-consuming.