How Long After Conditioning Water Can Fish Be Returned to the Tank?

How Long After Conditioning Water Can Fish Be Returned to the Tank?

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Current aquarium owners need to change the fish’s water, so it remains clean. Conditioning your water is a critical step in creating a great home for your fish.

Ensuring the well-being and safety of your fish starts with a clean tank of water. Water for your fish tank needs to be treated to create a healthy environment for your fish. Good quality water conditions only take minutes to work. Therefore, waiting 15 minutes provides ample time for the condition to disperse throughout the water.

Owning a fish tank is a rewarding and relaxing hobby. Following a few key steps to understand your water and how to make it safe for your fish will provide you hours of enjoyment with your aquarium. Continue reading for details to create a safe habitat for your fish.

Testing Your Water

The first step to ensuring a healthy aquatic environment for your fish is to know your water. To understand the chemicals in your water, you can test your water. After you see the results, you can find the best conditioner to mitigate the elements in your water that are harmful to fish.

If you are not comfortable testing your water, some fish or pet stores will do it for you. There may be a nominal charge for this service.

Water test kits are an integral component of your aquatic supplies for your fish. Your kit should test several parameters. Kits come as test strips or a liquid-based test. Both will provide the information you need.

Alternatively, you can call your water supplier to find out how your water is treated. Ask for the water chemist for your area. They can provide you information on the composition of your water and what chemicals have been used to treat your water.

Well or Tap Water

Looking at a clear glass of water, it is hard to image that the water could harm your fish. Whether you are using tap or well water to fill your fish tank, both n have chemicals in them that can be dangerous and toxic to fish.

Your water source will determine the type of conditioner that you need.

Tap water from municipal water sources has been disinfected and freed from bacteria. Without treatment, tap water would have harmful chemicals, minerals, and heavy metals. Chemical additives eliminate the components that would make the water unsafe for human consumption.

Water quality varies from city to city and from state to state. Your water will have different elements than another town’s water. Regulations are in place to monitor the safety of our drinking water.

While your well water might seem more wholesome than city tap water that is not necessarily true. Well water is unregulated. Your location will determine what your water contains.

Agricultural runoff might add nitrates and coliform to water. Industries can introduce volatile organic compounds to your water. Know your water, so you can condition it correctly is essential for your fish.

Chemicals in the Water


It may sound alarming to hear that you are drinking water that has been chlorinated. Well, the good news for us is that adding chlorine to our municipal drinking water works to disinfect and to kill bacteria that are harmful to people.

When cities and towns started adding chlorine to their water supply, countless lives were saved. Chlorine protects us from waterborne diseases such as cholera, typhoid fever, dysentery, and hepatitis A.

However, the chlorine also kills the good bacteria in the fish water. The good bacteria are needed to break down the ammonia and nitrites; both are found in fish waste.

Chlorine is toxic to fish. Since chlorine evaporates, it can be removed from water by letting it sit for about 24 hours. If this is the only harmful substance in your water, you can fill a bucket and let the water sit for a day while the chlorine evaporates.


Water systems rapidly consume the chlorine that is added; this causes the chlorine to be depleted before the water gets through the water system. Chloramine lasts longer in the water pipes making it a preferable product for many towns.

Chloramine is a more stable chemical than chlorine, so its use has increased over the past few years. Chloramine is a compound of chlorine and ammonia. This substance lasts longer than chlorine.

A compound formed from chlorine and ammonia; chloramine does not evaporate like chlorine. Therefore, it must be treated since it is also toxic to fish. So, you cannot let your water sit for 24 hours and think that it will be safe for fish.

Water Conditioners

Most water treatments work quickly and effectively to create a healthy environment for your fish. There are three key groupings of water conditioners:

·         Dechlorinators

·         Chloramine neutralizers

·         Complete conditioners

All three categories of liquid treatments will neutralize some of the chemicals that are harmful to your fish.

Dechlorinators neutralize the chlorine in your water. They act as magnets drawing the chlorine out creating chemical reactions that are positive for your fish. Remember, if your water also has ammonia, this category of water conditioner will not eliminate the ammonia.

Chloramine neutralizers are more encompassing than dechlorinators. Using a chloramine neutralizer will eliminate the ammonia in your water as well as the chlorine. Some of the chloramine neutralizers also remove heavy metals that can be found in water.

The complete water conditioning products are designed to focus on chlorine, ammonia, heavy metals, and copper. As their name implies, these water conditioners more thoroughly treat the water including pH balancing and protecting fish’s slime coat.  

All water sources will require some type of treatment to create a safe habitat for fish.

Related Questions

Do Conditioners Really Work?

Conditioners really do work. They create a safe environment for your fish by creating chemical reactions to eliminate the chemicals added to our water supply. Choosing a brand and type that addresses the harmful elements in your water will ensure happy fish.

Can You Over Condition Your Water?

Technically, yes, you can over condition your water. However, it is difficult to do. Be sure you know the size of your tank and how much water you are conditioning. Follow the directions on your conditioner, and your fish’s tank will provide a healthy world for them.

See Also:
What Does Blue Light in Fish Tank Do
How to Sterilize Fish Tank after Fish Died
How Long Do You Leave the Filter on in a Fish Tank