Can a goldfish change color?

A goldfish does not always have a beautiful orange color. Over the years a goldfish can change color slightly and that is quite normal.

Color changes are common in goldfish. Usually this is genetically determined and a goldfish can discolor with age. It can also occur as a result of diet, living environment and any illnesses .

Whether the goldfish regains its color depends on the cause and differs from fish to fish. In most cases, the color change is permanent, or the goldfish can regain some of its original color. If your goldfish has turned white or black , read on. There may be something wrong with your fish.

What color is a goldfish?

In the wild, a goldfish has an olive green or brown camouflage so that it is less noticeable in its natural environment and does not easily fall prey to predators. The orange, red, white, yellow or black color of commercial goldfish has been obtained through selective breeding.

A newborn goldfish is black to dark brown in color and will only turn orange over time.

Because not every fish has the perfect DNA, it is possible that your goldfish will change color or get spots at some point. This is no reason to worry.

However, a goldfish can also change color under the influence of living conditions. Think, for example, of illnesses, a wrong diet, poor water or too little light.

Why does a goldfish turn white?

A goldfish can turn white due to a number of factors. As the goldfish gets older, it can turn white. The white discoloration can also be a cause of illness, too little light, too little oxygen, a wrong diet or it is genetically determined.

1. The goldfish is old

Many goldfish slowly lose their color as they age. That’s just how nature works. Just as human hair turns gray with age, so does goldfish.

Old goldfish will be almost white in color with perhaps a yellow tint here and there, but that’s about it. That bright orange color is in any case nowhere to be seen.

If your goldfish has suddenly turned white from one day to the next, something else is going on.

2. Changes in the aquarium

Goldfish are very easy going and adapt well to the environment they are in, but the slightest change in their environment can cause them to change color.

For example, the pH value, temperature and hardness of the water can be a cause. In particular, a wrong pH value is known to take the color away from the goldfish. It is therefore best to measure this with a drop test.

The ideal temperature for goldfish is between 19 and 23 degrees. If you go out of the ideal temperature range, it won’t harm the goldfish, but it will adapt. This could make them slightly lighter in color.

They may even react when introducing new fish, plants or decorations to the aquarium. Suddenly their familiar environment changes and that could also contribute to the loss of the orange color, although the color difference is not that bad.

3. Too little light

The scales of goldfish contain pigment that reacts to light, namely natural sunlight.

In aquariums, it is recommended to always keep them out of sunlight to prevent large temperature fluctuations and algae growth. A goldfish then has no access to direct sunlight and can therefore turn white.

Your lamps hanging above the aquarium are often not strong enough or are not of the right color.

4. Too little oxygen

A cause of the white discoloration can be a lack of oxygen. The goldfish then become transparent white, as it were, it seems as if you can see through the fish.

You must immediately replace 50% of the water and find out the cause of the oxygen deficiency. If necessary, place an extra air stone in the aquarium to introduce more oxygen into the water.

Goldfish can tolerate fairly low oxygen levels, but don’t wait too long before it’s too late. The first sign of too little oxygen is gasping for air.

5. It’s genetically determined

Well, not every goldfish is perfect. The genes of a goldfish can also play a role, causing it to turn white or have white spots. There is very little you can do about this.

6. The wrong diet

Goldfish are known to eat anything that fits in their mouths. It is up to you to provide the fish with a properly balanced diet. For example, you could feed vegetables, fruit or insects.

Also switch to more expensive food, which is generally better for your fish. Sometimes it says on the packaging that it improves the color of your fish and that is often true. Cheap food always saves money.

7. Due to illness

Turning your goldfish white due to illness is always a painful subject. Of course you want the best for your goldfish, and if the above 6 points are not the cause, your goldfish is most likely sick or stressed.

A goldfish can turn white because it is sick or not feeling well. There is no disease that makes your fish white, but it is the result of poor resistance. Therefore, check whether your goldfish shows a disease , for example a decreased appetite, less active, falling scales, etc.

First of all, check whether your aquarium water is in optimal condition. This is often the source that makes your goldfish look bad. Goldfish are major polluters, which means that ammonia peaks cannot be ruled out. Are you unsure what it is? Then ask for advice from a vet who has a better view.

Why does a goldfish get black spots?

A goldfish can turn black over time due to genetic properties. The black discoloration can also be the result of ammonia poisoning or black spot disease. In the case of ammonia poisoning, acting quickly can be the difference between life and death.

I’ve already discussed why a goldfish can turn white, which is not uncommon. However, if your goldfish turns black, there may (sometimes) be something serious going on.

1. Ammonia Poisoning

I’ll start with the most dangerous thing: ammonia poisoning. This is by far the most common reason for a goldfish to turn black.

Usually the black color starts to appear at the tips of the fins and will slowly but surely spread all over the fish. This also occurs with other colored fish.

Ammonia is a toxic substance that is produced in an aquarium by bacteria and by the goldfish themselves. The reason that you should change your water regularly is to reduce the ammonia level, among other things. Bacteria in your filter also help with this, but often that is not enough.

What does ammonia do to your fish? Well, it actually burns your fish’s skin ! It also quickly affects the gills, causing the fish to produce mucus. Because of that slime, the fish is less able to extract oxygen from the water and will therefore slowly suffocate .

The black discoloration that occurs in a goldfish is a sign of recovery, a kind of scar tissue. This may mean that the ammonia levels in the water have decreased on their own. However, I advise you to check this to be sure.

Also check if your other fish show abnormal behavior. They may not be turning black yet, but they may be affected by the ammonia in the water.

Read Also: Ammonia Poisoning Fish – How Serious Is It?

2. Genetically determined

No ammonia poisoning? That is of course good news.

Goldfish begin life with a brown color and over time change to the color desired by the breeder, often orange. However, it cannot be ruled out that the fish will not discolour further.

This color change is mainly genetically determined. If you can see the genetic background of the previous generations with the breeder, it could give a glimpse of the color your goldfish will get over the years.

However, genetic errors also occur in fish and are therefore no guarantee of color retention. It may just be that your goldfish starts to get black spots after a few years.

From my own experience, I can say that goldfish that do not change color are extremely rare.

3. Black spot disease

Although black spot disease is rare, I will mention it anyway. This disease is more common in pond goldfish and less common in aquarium goldfish.

Black spot is a parasitic disease that a goldfish can contract from infected snails. The black spots are eggs that are in the skin of the goldfish and form a hard (black) layer. Eventually the eggs will burst open and the parasites will be released.

You can easily recognize black spot by black dots on the skin. Also, the fish can get itchy and want to rub its body against the glass or decoration.

To stop the life cycle of the parasites you must remove all snails from your tank. This will eventually kill the parasites and heal your fish. Although this is not the fastest solution, it does work.


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