4 Best Aquarium Water Conditioners: Voted By 170 Fish Keepers

Last Updated on 2023-07-05

Water conditioners are important for keeping your fish healthy by making tap water safe. But with so many options on the market, it can get really confusing! 

So, in this article I’ve compiled the best water conditioners out there to help you choose the right one for your fish. But you don’t need to just take my word for it. I also surveyed a whole bunch of fishkeepers to see what they thought the best water conditioner was! So, keep reading to find out everything you need to know!

What To Look For When Choosing Water Conditioner

Choosing the right water conditioner is crucial for your fish’s health and well-being. By picking a product that removes harmful chemicals, detoxifies heavy metals, supports gill health, and neutralizes ammonia and nitrite, you create a safe and healthy environment for your fish. 

Removing Harmful Chemicals

Tap water often contains chlorine and chloramine, which can be harmful to fish. To make sure your fish swim in water that’s free from these potentially dangerous chemicals, look for a water conditioner that removes them. That way, you can keep your fish safe and healthy.

Detoxifying Heavy Metals

Some tap water may have heavy metals like copper and lead, which can be toxic to fish. Choose a water conditioner that can get rid of these metals to keep your fish safe and healthy. And you should also look for products that say they can neutralize heavy metals.

Supporting Healthy Gills

Fish breathe through their gills, so it’s important to keep them healthy. Select a water conditioner that supports your fish’s gill function, and preferably, look for one that helps maintain the right balance of electrolytes. This reduces stress on the gills and makes it easier for your fish to breathe.

Detoxifying Ammonia and Nitrite

Ammonia and nitrite are harmful substances that can build up in your aquarium. They can cause stress and serious health problems for your fish. To prevent this, choose a water conditioner that detoxifies ammonia and nitrite. This creates a healthy environment for your fish to thrive.

Easy to Use

Nobody wants complicated aquarium maintenance. So, look for a water conditioner that’s easy to use. Fortunately most simplify the process of dechlorinating your water. It’s simply a case of measuring the correct amount and then adding it to the water. This way, you can spend more time enjoying your fish and less time worrying about water quality.

best aquarium water conditioner

What Exactly Do Water Conditioners Do?

After learning about what to look for when choosing water conditioners, it’s important to know the different types of water conditioners to know the best one to use in your tank. 

Remove Chlorine And Chloramine

The main reason to use water conditioners is because they remove chlorine and chloramine from your fish’s water. If you don’t remove both chlorine and chloramine from your fish’s water, then it can kill them incredibly quickly, so it’s essential to use a water conditioner for this reason.

Stress Coat Conditioners

Additionally, some water conditioners are also stress coat conditioners. These act like a soothing balm for your fish. With ingredients like aloe vera, they help calm and protect your fish’s skin and fins. These conditioners are great during stressful times, such as when introducing new fish or changing the water.

Beneficial Bacteria Conditioners

Beneficial bacteria conditioners are also important. They play a big role in establishing a healthy environment in your aquarium and contain helpful bacteria that break down harmful substances like ammonia and nitrite, however, there aren’t too many water conditioners that also contain beneficial bacteria.

What Are The Best Water Conditioners For Your Tank?

Let’s go over some of the most popular water conditioners among fishkeepers, such as Seachem Prime, API Stress Coat, and Aqueon Water Conditioner. We’ll consider the experiences and opinions of fellow fishkeepers who have used the products and what makes them great choices.

I asked over 170 fishkeepers, which one they loved the most, and as you can see, Seachem prime one by a landslide!

best water conditioner 1
best water conditioner 2

1. Seachem Prime

Seachem Prime is the most popular water conditioner known for its effectiveness and versatility. Aside from removing chlorine and chloramine, it also detoxifies ammonia, nitrite, and nitrate. This makes it an excellent choice for establishing and maintaining a healthy aquarium.


  • Provides comprehensive water conditioning by neutralizing harmful substances.
  • Detoxifies ammonia, nitrite, and nitrate, promoting fish health.
  • Economical, as a small amount of Prime goes a long way.
  • Works quickly to make tap water safe for immediate use.
  • Doesn’t affect pH levels in the water.


  • Strong odor, which some users find unpleasant.
  • Requires precise measurement for accurate dosing.
  • Can cause foaming if overdosed.
Seachem Prime Fresh and Saltwater Conditioner – Chemical Remover and Detoxifier 500 ml
  • POWERFUL TREATMENT: Seachem Prime is a complete and concentrated conditioner for both freshwater and saltwater fish tanks, working hard to remove chlorine and chloramine.

2. API Stress Coat

API Stress Coat is not only a water conditioner but also a stress reducer and fish health enhancer. It has aloe vera, which helps to soothe and heal fish, making it a popular choice for those looking to create a calming environment for their fish.


  • Relieves fish stress and helps in the healing of damaged fins and skin.
  • Forms a protective slime coat on fish, guarding against external parasites.
  • Detoxifies harmful substances in tap water, including chlorine and heavy metals.
  • Promotes the overall health and well-being of fish.
  • Easy to use and measure.


  • Some users find the scent of the product overpowering.
  • May cause slight cloudiness in the water initially.
  • Doesn’t neutralize ammonia and nitrite as other conditioners.
API STRESS COAT Aquarium Water Conditioner 16-Ounce Bottle
  • Contains one (1) API STRESS COAT Aquarium Water Conditioner 16-Ounce Bottle

3. Seachem Safe

Seachem Safe is another water conditioner from Seachem that has gained positive reviews for its effectiveness in maintaining water quality. Here are the features that make it worth considering:


  • Removes chlorine and chloramine, ensuring safe water for your fish.
  • Maintains a clean and safe environment in your tank by eliminating harmful substances like ammonia, nitrite, and nitrate.
  • Suitable for both freshwater and saltwater setups.
  • A small amount of product goes a long way, providing excellent value for your money.
  • Long-lasting effects, reducing the need for frequent conditioning.
  • Compatible with various filtration systems.


  • Compared to other options, it may be slightly more expensive.
  • Requires accurate dosing due to its concentrated nature.
Seachem Safe 1 Kilo
  • This product is easy to use
  • This product adds a great value
  • This product is manufactured in United States

4. Aqueon Water Conditioner

Lastly, another water conditioner that was recommended by fish keepers was Aqueon Water Conditioner. While it didn’t get NEARLY the same recommendations from my test group as other conditioners, it was still recommended enough to be worth mentioning here.


  • Instantly removes chlorine and chloramine from tap water.
  • Enhances the natural slime coat on fish, providing protection against stress and infection.
  • Cost-effective and readily available.
  • Simple to use, with clear dosage instructions.
  • Works well for both freshwater and saltwater aquariums.


  • Some users report a lingering scent after application.
  • Doesn’t address other harmful substances like ammonia and nitrite.
  • May require higher doses for heavily chlorinated water.
Aqueon Aquarium Fish Tank Water Conditioner Bottle, 16 ounces
  • Use when filling aquarium with tap water, performing water changes or adding fish

What’s The Difference Between Chlorine And Chloramine?

When it comes to taking care of your fish, it’s important to know the difference between chlorine and chloramine in your tap water.

Chlorine is a chemical that’s added to tap water to keep it free from harmful bacteria and make it safe to drink. It can evaporate on its own if you let the water sit out for a while. 

However, if you use water with chlorine directly in your fish tank, it can harm your fish by affecting their delicate gills and making it hard for them to breathe.

Chloramine, on the other hand, is a combination of chlorine and ammonia. Water treatment plants use chloramine as a disinfectant because it provides longer-lasting protection. Unlike chlorine, chloramine doesn’t easily go away when you let the water sit out. 

This means you can’t just wait for it to disappear before adding tap water to your fish tank.

To make tap water safe for your fish, you need to use a water conditioner or dechlorinator specifically designed to remove chlorine or neutralize chloramine. 

These products contain special ingredients that get rid of chlorine or break down chloramine, making the water safe for your fish to swim in. Overall, it’s important to use a water conditioner that suits your needs and the type of water in your area.

Can You Add Fish To Your Tank Without A Water Conditioner?

It’s highly recommended to always use a water conditioner when adding fish to your tank. Water conditioners remove harmful chemicals, detoxify the water, and maintain stable conditions for the well-being of your fish. 

Let’s dive deeper into this:

Firstly, tap water often contains chemicals like chlorine and chloramine, which can harm your fish. However, water conditioners are specifically made to remove these chemicals and make the water safe for your fish.

Second, water conditioners also help get rid of other harmful substances that can build up in the water, such as ammonia, nitrite, and nitrate. These substances can be toxic to fish and cause health problems.

Moreover, using a water conditioner helps maintain stable water conditions, which is crucial for the well-being of your fish. Sudden changes in water quality can stress the fish and make them more prone to illnesses.

On top of that, fish are sensitive creatures, and they can easily get stressed when exposed to poor water conditions. Using a water conditioner helps create a consistent and suitable environment, reducing stress and promoting the overall health of your fish.

How To Add Fish To A Fish Tank Without Water Conditioner

It is generally not advisable to add fish to a fish tank without using a water conditioner. However, if you find yourself in a situation where you don’t have a water conditioner available, here are a few steps you can take to minimize the potential risks for your fish.

Preparation is Key

Before adding fish, make sure your tank is properly set up and cycled. This means having a fully established biological filter that can handle the waste produced by your fish. And remember, a cycled tank helps maintain water quality and reduces stress on the fish.

Use Aged Water

Instead of using tap water directly, fill your tank with tap water and let it sit for at least 24-48 hours. This allows some of the chlorine present in tap water to dissipate naturally. Although it won’t remove all the harmful chemicals, it can help reduce their concentration.

Acclimate the Fish

Before introducing the fish to the tank, it’s important to acclimate them to the new water conditions. Float the fish bag or container in the tank for about 15-20 minutes to equalize the water temperature. 

Then, gradually add small amounts of tank water to the bag for another 15-20 minutes to help the fish adjust to the new water parameters.

Slowly Add Your Fish

Once you’ve acclimated the fish, you can now add them to the tank. You should use a net to make sure as little water from the bag as possible goes into the tank. (This reduces the risk of bacteria or parasites being transferred to the tank.)

Once you’ve done this, you should also turn the lights off to make sure that your fish feel safe and more relaxed in the tank.

Monitor Water Parameters

Keep a close eye on the water parameters, such as ammonia, nitrite, and nitrate levels in the following days. Without a water conditioner, these levels may fluctuate more, which is dangerous to your fish. So, perform regular water tests and be prepared to take immediate action if any issues arise.

Observe Fish Behavior

Watch the fish closely for any signs of stress, such as excessive hiding, loss of appetite, or abnormal behavior. If you notice any concerning symptoms, check out some of the fish-illness-related articles on this website or visit your trusted veterinarian.

And remember, adding fish without a water conditioner should only be a temporary solution. As soon as possible, obtain a reliable water conditioner and treat the water properly to ensure the long-term health and well-being of your fish.

When Should You Use Water Conditioner?

Water conditioners are specifically designed to make tap water safe for your fish. In fact, you should always use a water conditioner when adding new water to your fish tank or aquarium. However, there are other instances when you should use a water conditioner:

Water Changes

Whenever you do regular water changes to keep your tank clean and healthy, it’s important to use a water conditioner.

Remember, tap water contains chemicals like chlorine and chloramine that can harm your fish. Water conditioners help neutralize these chemicals, making the water safe for your fish.

Setting up a New Tank

When you’re starting a new tank, you need to fill it with fresh water. Since tap water usually has chlorine or chloramine, using a water conditioner right from the start is crucial. This ensures a safe environment for your fish from the beginning.

Introducing New Fish

If you’re adding new fish to your existing tank, you need to treat the water they’ll be in. This prevents any harmful chemicals  or impurities in the water from affecting the new fish during acclimation. Using a water conditioner ensures a smooth and stress-free transition for the new fish.

Treating Sick Fish

Sometimes, when your fish are sick and need medication, the treatments can affect the water quality. In such cases, water conditioners come to the rescue. They help neutralize any harmful effects of the medications, maintaining a safe environment for your fish.

Handling Emergencies

In emergency situations where you need to perform immediate water changes or adjust the water conditions, a water conditioner is essential. It quickly makes the water safe for your fish, reducing stress and potential harm caused by sudden changes.


How Much Water Conditioner Should You Use?

The dosage of water conditioner depends on the size of your tank and the amount of water you’re treating. Follow the instructions on the product label for the recommended dosage.

As a general guideline, use about 1ml of water conditioner for every 10 gallons of water.

How Often To Use Water Conditioner?

To ensure a safe environment for your fish, use a water conditioner during regular water changes, when adding fresh water, and when introducing new fish to your tank. It helps neutralize harmful chemicals and maintain their well-being.


Choosing the right water conditioner is absolutely vital for your fish’s well-being. Remember to follow the instructions and use the recommended amount of conditioner for the best results.

By regularly using a high-quality water conditioner, you can create a safe environment for your fish to thrive in.

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