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Neon Tetra Fungus

neon tetra fungus


Have you got a Neon Tetra that is not looking particularly well? If so, you may be wondering whether it could have a fungal infection or something else concerning. It’s always frightening when a fish is sick, so let’s find out more about this.

Like all fish, Neon Tetra can suffer from fungal infections, and these are something that you should be on the lookout for, as they will kill your fish and will sometimes spread throughout a shoal, infecting multiple fish. Fungal infections can be difficult to deal with, and may even be difficult to diagnose.

What Are Fish Fungus?

Fungal infections can take a variety of forms, and will infect all kinds of fish, including Neon Tetras. They aren’t as common as bacterial diseases or parasites, but they do occur, and they can either be internal or external.

External infections – unsurprisingly – are easier to spot, and usually appear as white growths on your fish’s skin. These are sometimes referred to as cotton growths, because of their fluffy appearance.

Internal fungal infections are harder to see, but you may occasionally catch a glimpse of something white inside a fish’s mouth as it feeds, especially if it comes to the surface to do so. Keep an eye on your fish when they open their mouths, particularly if you suspect one or more may be carrying a fungus.

Many issues can cause fungal infections, including things like poor water quality, open wounds, infections, and more. On the whole, fungal infections do not spread as quickly as bacteria or parasites, but they can be difficult to get rid of, and they will often gradually infect more fish.

How Do You Treat Neon Tetra Fungus?

If one of your Neon Tetras has developed a fungus on its body, there are a few things that you can do to treat this. However, be aware before you start that fungus will usually only successfully attack your fish if there is some problem with the tank environment, or the fish is very stressed. In general, fish only become vulnerable to fungal infections when there are other issues.

You should therefore start by checking your tank parameters are good and correcting any imbalances in the levels. You should also check whether anything is stressing your fish out. Being kept with incompatible species, being overcrowded, being bullied, or the water being the wrong temperature could cause stress.

Remember to clean the tank and look out for any nutrient deficiencies too, as this will make your fish more likely to recover. You may want to change the food that you are providing, or offer some additional options to boost your fish’s resilience.

There’s no point in treating the fish until you have corrected the conditions, as it is likely to get reinfected, or remain infected. Once the tank’s parameters are balanced again, you can start treating your fish.

To do this, you should use a commercial fungal treatment that is suitable for Neon Tetras. There are many options, including things like Maracyn or Anti Fungus and Finrot should work well for getting rid of most kinds of fungal issues. Maracyn works well on the mouth, whereas you may want something like ICH-X for other fungal infections.

Follow the directions on the packaging so you know you are treating the fish correctly. Don’t stop treating them before the manufacturer’s stated time period, or the fungus may reappear.

While treating your fish, you should also make sure you are maintaining the tank conditions and feeding the fish well. Keep on top of any bullying.

Why Is My Neon Tetra Turning White?

Your Neon Tetra may be turning white for a whole range of reasons. Some are easy to correct, while others are harder. A few common reasons include things like poor water conditions, stress, and improper temperature. The latter of these is a particularly commonest problem, so make sure that your fish are warm enough and you haven’t accidentally brought the temperature down with water changes.

Alternatively, your fish may have a fungus. Fungal infections often result in white, fuzzy spots on the body. These can appear on any part, and may be large or small – but they will usually start off small and gradually gain size as the fungus progresses. If you think your fish has a fungal infection, treat it as described above.

Another common issue is Neon Tetra Disease, which can affect your fish’s colors. You may notice the brightness of your fish’s scales fading, and the blues and reds might become dull. If this happens, it’s a clear sign that your Neon Tetra is sick.

Unfortunately, Neon Tetra Disease is not treatable and you will not be able to save the affected fish. However, you may be able to prevent the disease from spreading if you are prompt about removing the sick fish and cleaning the tank. You should euthanize the fish that has been infected.

Frustratingly, Neon Tetra Disease can look a lot like a fungal infection, because it also results in small white spots where the color of your fish has faded. You should try to diagnose with care.

The disease is often accompanied by odd behavioral traits, such as swimming erratically. You may see bloating, a curved spine, and difficulty with moving through the water. In some cases, you’ll see other problems, such as fin rot.

Look out for these signs and remove the fish as soon as possible. The others may nip at it or try to eat it, and this will pass the disease on to them. If the affected fish dies and is left in the tank, the others will eat it, and will become infected. Fast action is critical if you want to save your aquarium.


Neon Tetra fish can suffer from fungal infections, just like other fish, but they can also suffer from something known as Neon Tetra Disease. This will cause white patches on the body, which can look like fungal infections. It is important to differentiate between the two, because a fish with Neon Tetra Disease needs to be removed and euthanized, while a fish with a fungal infection can usually be treated.

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Erik Miller

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Hello, there. Welcome to my blog. I am Erik and I’m the main editor of Sealife Planet website.

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