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Goldfish Turning Black: What Should I Do?

Whenever you start to notice your goldfish is turning black or that it has black spots appearing, it is easy to panic. Goldfish are usually bright and colorful, so they can send you into a frenzy of worry whenever their normal bright colors are replaced by dark patches.

Remember whenever you first start to notice the black spots or patches to investigate before you worry too much. There are several reasons why your goldfish might be turning black. Not all of these reasons are necessarily bad either.

So why is my goldfish turning black? This article should help to explain why your goldfish might be turning black if you should be concerned or worried, and what you might be able to do in order to help your goldfish.

Should I be Worried Whenever I Notice my Goldfish Turning Black?

Goldfish are a great pet for people with children, people who are allergic to furry animals, or someone who just does not have much time on their hands. Goldfish are resilient and pretty easy to take care of. The most important thing when you own a goldfish is to remember to keep their aquarium nice and clean at all times.

You can find goldfish ready to take home with you at almost any pet store, and they are usually cheap as well. When people see a goldfish, the most notable feature is the shining gold color. Your goldfish is usually vibrant and pristine, so whenever they go from radiant to black it can be very alarming.

It is much more common for a goldfish to turn white than to turn black. So don’t take it lightly either whenever your goldfish appears to darken up!

There are a number of reasons, some of them definitely should be a cause for concern. Your fish darkening could be a sign that they are internally suffering, so regardless you should get your goldfish checked out just to be safe rather than sorry. Having said that, it does not necessarily mean that your goldfish is suffering or even in danger.

So in order to determine if your goldfish turning black is detrimental, you have to first understand what is making your goldfish turn black. It is important to learn to recognize possible symptoms of illness in your goldfish. It is also very important to get your goldfish the appropriate care and attention in order to make sure your goldfish remains healthy.

Common Reasons Why Your Goldfish Is Turning Black

There are several reasons as to why your goldfish might be turning black. Goldfish turning black is very rare, no matter what type of goldfish you have. Since it is rare for a goldfish to turn black, it is important that you take all possible reasons into consideration. The good and the bad reasons.

Once you have determined why your goldfish is turning black, you will be able to help your fish more efficiently.

Black is a very unbalanced color among all types of goldfish. Usually, goldfish that are all black tend to turn yellow or gold. Gold or yellow is the most common color for your goldfish to have. It is also important to note that goldfish can change colors depending on their surrounding. Goldfish are known for changing colors frequently.

1. Ammonia in Your Aquarium Can Cause Your Goldfish to Turn Black

Ammonia burns are one of the most common reasons why your goldfish might be turning black. Ammonia is actually a very toxic chemical that builds up in your fish aquarium. Whenever your fish produces waste, ammonia is made. Usually, the ammonia will be released through the gills.

Ammonia is also produced whenever there is uneaten food in your fish aquarium that decomposes. This is a silent killer for your fish, and if you do not have a proper filtration and cycling system setup for your aquarium ammonia build-up can and likely will be a serious issue.

It is very important to regularly clean and changes the water in your aquarium. If the tank is not cleaned and maintained ammonia levels will rise profusely and this can be very detrimental to your goldfish. Black spots on your goldfish caused by ammonia will usually first appear on the fins of your goldfish.

The chemical is burning your fish’s skin. You cannot see ammonia in the water itself, so you will need to use a water testing kit. The ammonia level should be at 0 at all times. Even a drop of the chemical is too much and could potentially kill your goldfish, or any other fish in your aquarium.

Genetics Might be the Reason Your Goldfish is Turning Black
Genetics Might be the Reason Your Goldfish is Turning Black

2. Genetics Might be the Reason Your Goldfish is Turning Black

This is a far less concerning reason as to why your goldfish might be turning black. Depending on the type of goldfish you have, it is common and expected for them to have color changes throughout their entire lives. It is still rare for black to be one of the colors your goldfish will turn to. but that does not mean it is not possible.

Goldfish that are “mixed breed” are the most common ones who are typically known to go through such drastic color changes during their lives. These types are typically the cheapest goldfish that you will find at the local pet stores. They might already have odd color patterns whenever you see them at the store.

Usually, the changes happen as the goldfish goes from being young to being an adult. Normally, if your goldfish develops black patches or spots because of their genetic make-up, it does not last very long. Eventually, as they transition into their adult stage the colors will even out.

Whenever your goldfish begins turning black due to genetic makeup it is not a cause for concern, nor is it life-threatening. Just sit back and enjoy the color show if genetics is the cause of your goldfish turning black!

Disease Might be Another Reason Your Goldfish is Turning Black
Disease Might be Another Reason Your Goldfish is Turning Black

3. Disease Might be Another Reason Your Goldfish is Turning Black

It is very uncommon for a goldfish to start turning black due to disease but that does not mean it is impossible. There are also certain types of parasites that can sometimes infest your fish tank. One of these parasites typically comes with snails. If you notice your goldfish turning black on their fins and other areas, and you also have snails in your aquarium.

This type of parasite might be the culprit. The parasite burrows into the skin of your goldfish and lays its eggs. Whenever this happens it creates a hard cyst on your goldfish’s fins and can result in black spots appearing. Whenever that happens you will want to remove your snails from the aquarium which should fix the issues.

Keep in mind, it can take up to 2 months for the black spots to completely disappear from your fish altogether. If the problem is extremely severe and does not seem to be getting better you can also opt to use an aquatic parasite treatment. You can find these types of treatments typically at pet stores.

Opting to use an aquatic parasite treatment will yield faster results and things should go back to normal much quicker. Keep in mind that this option will also cost money. How much you can expect to pay for an aquatic parasite treatment depends on the pet store you go through and the treatment you use.

Commonly Asked Questions About Your Goldfish Turning Black

What is the best way to keep ammonia out of my fish tank?

The best way to keep ammonia out of your fish tank is to ensure that you keep your aquarium as clean as possible. Make sure your filtration and water cycle system is working well. Another way to handle ammonia whenever your aquarium water tests positive for it is to do a partial water change.

Add more water to your fish tank, the freshwater will not contain ammonia and will help to dilute it. Sometimes it helps to have multiple filters in your aquarium, this is also dependent on how big your aquarium is. For example, a smaller fish tank might not be big enough for more than one filter while larger fish tanks and aquariums will have more room, in turn allowing for more filters.

Make sure to unclog and regularly clean your filters so that they work quickly efficiently. If your filter is too dirty or clogged it will not do its job which could result in more ammonia growth. Make sure that you regularly remove any dead plants or uneaten food from the aquarium as well. Your aquarium could also benefit from keeping living plants in the tank such as java fern or java moss.

Not only can keeping living plants in your aquarium help with ammonia levels, keeping living plants in your aquarium also helps produce oxygen for your fish as well.

What is the best way to increase the color of my goldfish?

The best way to increase vibrant colors on your goldfish is to give them color-enhancing food. There are many different types of food you can feed your fish that are rich in nutrients that your fish needs in order to remain healthy and happy; the vibrancy in their color increasing is a product of this.

Make sure that whenever you get your goldfish that you speak to the people at the pet store about the diet you should keep your goldfish on to ensure they remain healthy and colorful. It is also very important to make sure your aquarium is properly lit.

Making sure your aquarium is properly lit and your fish is getting the right amount of light does not necessarily increase the color of your goldfish, but it does help fight against fading colors in your goldfish. So make sure you get a light for your aquarium in order to make sure that your fish gets plenty of ‘sunlight.

Happy and healthy goldfish
Happy and healthy goldfish

How can I tell if my goldfish is happy and healthy?

A healthy goldfish will be regularly swimming, if you notice your goldfish is sinking or bobbing unsteadily then there is a problem. Your goldfish should eat regularly whenever you feed them. Make sure you do not feed your goldfish too much, feed the goldfish the pet store recommended amount of food.

If you have other fish or other goldfish in your aquarium monitor their reactions with their peers. Some fish breeds are known for being aggressive and should never be kept in the same aquarium as other fish. Your goldfish should appear to be bright and shiny, that is the biggest sign of a happy and healthy goldfish.

This Guide Should Provide You With the Knowledge You Need For Your Goldfish

After reading this guide you should have a better understanding of why your goldfish might be turning black. It can be very disheartening and extremely sad to see your once bright and elegant goldfish turn dark. Remember that this does not necessarily mean that your goldfish life is in danger, but you should always take it seriously and get to the bottom of it as fast as possible.

Whenever you first notice your goldfish turning black it is important to take action immediately. The longer you wait to take action, the more detrimental the situation might become. The sooner you figure out why your goldfish is turning black the sooner you can help them get back to their bright, colorful, and happy selves.

Keep in mind that your goldfish’s appearance will change over time, and that is always part of the fun when it comes to owning such an elegant fish.


In Conclusion

The shortest answer for why your goldfish is turning black is likely due to either unclean water that is resulting in ammonia levels in your fish tank, or it’s from snails in your tank that might be causing disease within your aquarium. Both of these can be treated by removing any snails or disease carriers and cleaning the water in your fish tank.

If you have any more questions, comments, or concerns please comment them down below.

About Ava Wellington

Hi, my name is Ava and I am a editor for GuideYourPet. I love pets, and am the owner of 2 horses and 2 dogs! I have loved pets all my life, and have owned everything from bearded dragons to snakes! I am excited to help you take the best care of your pet!