How To Remove Copper From The Aquarium [6 Effective Ways]

Having a happy aquarium with lively fish is awesome! But sometimes, things don’t go as planned. 

One of those things is copper sneaking into your fish tank. You see, copper is okay in tiny amounts, but if there’s too much, it’s like trouble knocking on your fish’s door. 

In this guide, I’ll discuss where copper comes from, how to check if it’s there, and what you can do to remove copper from the aquarium. Let’s dive in and figure it all out!

What Causes Copper in Fish Tanks?

Copper can sneak into your fish tank from different places, like when the water isn’t clean, things you put in the tank, medicines for the fish, and even the pipes that bring water to the tank. 

Sometimes, the water that comes out of your tap might already have a bit of copper in it because of the pipes or other stuff in the environment.

When there’s too much copper in the tank, it’s not good for your fish. It’s like when we eat too much candy – it makes us feel sick. High levels of copper can make your fish stressed and not feeling well. 

Imagine if you had to breathe through a straw – that’s how fish might feel with too much copper. It can even hurt their skin and make them very sick. 

So, it’s important to keep an eye out for copper and get rid of it to keep your fish happy and healthy.

How Do You Test For Copper in Water?

Testing the water to see if there’s any copper in it is super important. It’s like checking if there’s something harmful in your food before you eat it. 

To do this, you can use special kits that are made just for checking copper levels in your fish tank water. These kits are made to be easy to use.

Here’s how they work: You take a little bit of water from your tank and mix it with a special liquid in the kit. 

This liquid can change color depending on how much copper is in the water. It’s kind of like when you mix paint colors – you get a new color. In this case, the color tells you how much copper is in the water.

If the color turns out to be a certain way, it means there’s too much copper. That’s like a warning sign that says, “Hey, there’s more copper than there should be.

When you see this warning, it’s time to do something about it. You need to take steps to get rid of the extra copper and make sure your fish can swim around in safe and healthy water.

Methods To Remove Copper From The Aquarium

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1. Test The Water

Just like checking the weather before going outside, you should regularly check your fish tank water for copper. 

This is an important step in keeping your fish healthy. Remember those kits we talked about earlier? They’re like special tools that can tell you if there’s too much copper in the water.

So, from time to time, take a small sample of water from your tank and use the kit. It’s not complicated – mix the water with a special liquid from the kit, and it will change color. This color tells you if there’s a lot or just a little copper in the water. 

By doing this regularly, you can keep an eye on how well the methods you’re using to remove copper are working. If you see the color changing too much, it’s a sign that you might need to take extra steps to keep your fish safe.

2. Get Rid of Anything with Copper

Look closely at your fish tank and find anything that has copper in it. This could be things like decorations or ornaments. These items might be letting copper sneak into the water, and that’s not good for your fish.

Pick up those copper-containing things and gently remove them from your tank. It’s like saying goodbye to things that are causing trouble. 

By doing this, you’re stopping extra copper from getting into the water and bothering your fish.

3. Change The Water

To make the water healthier for your fish, you can do something called a partial water change.

Here’s how: Take out a part of the old water from your tank – not all of it, just some. Then, add in clean water that doesn’t have any chlorine in it. 

Think of it as swapping out the old water for new water, like changing the sheets on your bed. This is like giving your fish a breath of fresh air.

By doing this, you’re diluting the copper in the water. It’s like adding a little water to your juice to make it less strong. Your fish will enjoy swimming in water that’s cleaner and safer for them.

4. Use Activated Carbon

Activated carbon is the incredible stuff that can actually soak up copper particles from the water, just like a sponge soaks up water.

Put activated carbon into your filter. It’s like giving your filter a powerful tool to catch the copper. As water flows through the filter, the activated carbon works its magic and traps the copper. It’s like having a secret agent that captures the bad guys.

After a while, the activated carbon becomes tired and can’t catch copper anymore. So, make sure to replace it when needed, following the instructions. 

This way, activated carbon will always be ready to keep your fish tank water clean and free from too much copper.

5. Apply a Product Designed to Remove Copper

There’s a special solution available just for tackling copper in your fish tank. Aquarium stores have products made especially to get rid of copper from the water.

Here’s how to put these tools to work: Get one of these copper-removing products from the store. Follow the instructions on the package – it’s like following a recipe. Mix it in with your tank water according to the directions. This product is like a superhero that fights copper.

Remember, superheroes work best when you use them right. So, be sure to read and follow the instructions carefully. 

This way, you’re ensuring that the product works safely and effectively, making your fish tank a better place for your underwater friends. Your fish will be swimming with joy.

6. Retest the Water

Now that you’ve taken steps to kick out the copper, it’s time to make sure it’s really gone.

Here’s what to do: After you’ve done all the things to remove copper, grab that copper test kit again. Use it to test your tank water, just like before. This time, you’re seeing if all your hard work paid off. 

If the color on the test shows that copper levels are lower, you’re on the right track! It’s like getting a thumbs-up from your teacher.

Checking again is like being sure your room is super clean before your guests arrive. If the copper is in a safe range, your fish will be much happier and healthier. 

What are The Recommended Levels of Copper in The Aquarium Water?

Think of copper levels in your fish tank like Goldilocks and the Three Bears – not too much, not too little, but just right! The right amount of copper is really important for your fish to stay happy and healthy.

Aquarium experts say that having about 0.05 to 0.20 parts of copper in a million parts of water is just right. It’s like adding a pinch of salt to your food – not too much and not too little. When the copper is in this range, your fish and other underwater pals are safe and sound.

Having too much copper is like eating too much candy – it can make your fish feel sick and uncomfortable. 

So, it’s good to keep an eye on the copper levels and make sure they’re not too high or too low. This way, your fish can swim around and enjoy their underwater home without any worries.

What Are the Potential Side Effects of Copper in Aquarium Water?

Just like that, having too much copper in your fish tank can be really bad for your underwater buddies.

If there’s too much copper, your fish might start acting strange. They could become very tired and lazy, not wanting to swim around or play like they usually do. 

They might lose their appetite and not want to eat their fishy food. Breathing could become hard for them, like when you have a bad cold. You might even notice their skin and gills looking weird or damaged.

In really serious cases, if you don’t do anything about the extra copper, your fish could even die. It’s like if we don’t go to the doctor when we’re really sick – things can get worse. 

So, it’s super important to keep the copper levels just right so your fish can be happy and healthy, swimming around without any troubles.


Making sure your fish have a good home is really important. You want them to be happy and healthy, right? So, it’s crucial to have a nice and safe place for them to swim. 

Doing regular tests, finding out where copper might be coming from, and working hard to get rid of it are big steps in the right direction. 

When you follow the things we talked about in this guide, you’re like a superhero for your fish! They’ll have a wonderful place to live, swim, and enjoy their underwater world.


Is copper toxic to aquarium fish?

Yes, copper can be harmful to fish in your aquarium. While a little bit of copper is okay, too much of it can make your fish feel sick and unwell.

It’s like eating too much candy – it’s not good for you. So, it’s important to make sure there’s not too much copper in your fish tank water.

How long can you keep fish in copper?

Fish don’t like being in the water with a lot of copper. If they stay in it for too long, it can be bad for their health.

So, if you’re using treatments with copper to help your fish, you should follow the instructions carefully. Once the treatment time is over, it’s best to move your fish back to their normal tank with clean water.

Does charcoal absorb copper?

Yes, charcoal can help take out copper from the water. It’s like a sponge that soaks up things you don’t want.

If you have a filter with activated charcoal in your tank, it can help remove some of the extra copper and keep your fish safer. Just remember to change the charcoal regularly so it keeps working well.

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