In particular, Amyloodinium ocellatum, commonly referred to as “velvet,” is a single-celled dinoflagellate capable of causing disease in betta fish. Velvet’s life cycle is quite similar to that of Cryptocaryon irritans (ich).

Thus, Velvet dinospores will usually invade the gills first. Also, sometimes, it kills the fish right then due to asphyxiation. Therefore, if this happens, you may never see physical evidence of velvet on the skin & fins. Hence, it is important to observe some key behavioral symptoms of velvet.

What Is Velvet?

In particular, Velvet is a disease caused by parasites in your tank water. Thus, it has many different names such as

  • Rust,
  • Gold Dust Disease,
  • Oödinium,
  • Coral Disease, and
  • Velvet.

Thus, if you hear someone mention any of these diseases, they are talking about the same one.

Particularly, the reason it gets these names is that one of the main symptoms makes your fish look like it’s covered in gold dust or rust. Your betta fish will get his majestic color dulled by gold like coating over his body.

However, there is more than only one symptom associated with velvet.

Symptoms of Velvet in Betta Fish

In the early stages, you may not notice a gold coating over your betta fish. Specifically, the gold coating occurs due to your fish producing excess mucus. This is an attempt by the betta to try and fight the infection.

Ways to differentiate velvet from ich

In general, velvet trophonts are much smaller than ich. Usually, they range in size from 10-80 micrometers in diameter. Likewise, they are perfectly round.

Also, ich trophonts are more oval-shaped and range in size from 48 x 27 to 452 x 360 micrometers. Meanwhile, both start off small but then grow in size before dropping off.

Often, people say that velvet makes a fish look like it has been dusted with a fine powder. Whereas, ich is much more like salt grains.

By and large, if you can count the number of white dots on your fish, then you are probably dealing with ich. However, if they are too numerous to count, it is most likely velvet.

The Importance of Recognizing Key Behavioral Symptoms of Velvet in Bettas

Usually, once velvet spreads to the body, the fish is heavily infected. Thus, the prognosis is bleak. Often, velvet cannot be managed. In contrast, ich sometimes is. This is due to its sheer overwhelming numbers.

Meanwhile, sometimes it is possible in a very large aquarium if you also utilize equipment (e.g. UV sterilizer, diatom filter). Particularly, these equipment are capable of removing free swimmers from the water column.

Also, survivors of velvet are usually

  • Clownfish, and
  • other fish with a thick mucous coat like wrasses & dragonets.

Similarly, a very small percentage of fish are capable of building up either natural or temporary immunity to velvet.

Common Early Symptoms

In particular, one of the earliest signs you’ll begin to notice is that your betta will behave differently. Usually, they begin rubbing their bodies against anything in the tank.

Particularly, this is because the parasite is irritating them. Thus, if they’re rubbing their body against things it’s because they’re trying to get the parasite off. However, this symptom isn’t just peculiar to velvet.

Likewise, the “gold rust” occurs in the earlier stages of velvet. Mostly, it occurs after the above symptom. Meanwhile, remember, it’s not the disease itself that’s making your fish look like it’s covered in gold dust. Rather, it’s your fish’s reaction to the disease.


  • lethargy and
  • loss of appetite are another sign.

Thus, as your fish becomes sicker they will become weak. Therefore, being weak will cause them to become lethargic and lose their appetite.

If you catch your betta fish in the early stages of velvet, then the chances are he’s going to be fine. However, ensure to watch out for the later stages of velvet.

Finally, once velvet gets this far, it can be a lot harder to treat.

Common Late Stage Symptoms

Eyes cloud over – Usually, this happens when there’s a lot of bacteria in your tank. Likewise, cloudy eyes can be caused by a lot of other things.

However, if you notice this symptom and none of the others then it may be a cloudy eye.

Your betta will keep his fins very close to his body – Again, this may not be caused by velvet because it’s often an indicator of many diseases. However, when you notice it along with some of the other symptoms, then you should start treating your betta for velvet.

Skin detachment, and ulcers in the skin – As your betta fish becomes more infected, you’ll notice

  • skin beginning to detach or
  • ulcers in the skin.

Meanwhile, this could be caused by two reasons.

  • The parasite is eating into your betta more and more, or
  • because your betta is constantly rubbing against things.

However, if you notice skin detaching from the fins of your betta fish and not the body then your betta is suffering from fin rot. This is another dangerous disease that can be fatal for betas.

Your betta fish eyes may begin to protrude out as well– Generally, this happens when fluid starts leaking into an area behind the eye. Therefore, forcing the eye to pop out.

However, you should not mistake this for Popeye which is another disease.

How to Treat Velvet In Betta Fish

So, now that you’re aware of the symptoms. Hence, you should have a good idea about whether your betta is suffering from velvet.

Therefore, if you think that it’s velvet then follow the steps below. Luckily, velvet is curable. Also, if you follow the guidelines below your betta has a good chance of surviving.

First, we are going to assume that your betta is in a tank by himself. However, if he’s not, you’ll need to set up a quarantine tank for this procedure. Otherwise, you will be treating fish for a sickness they don’t have. And this will affect their immune system.

The Three Keys To Treating Velvet

Early on, there are three things you’re going to need to treat velvet in your betta fish. Specifically, these are

  • heat,
  • salt, and
  • darkness.

Usually, when starved of light, the parasite that causes velvet will die. Also, luckily, the disease can only survive without a host for a couple of days before perishing as well. Thus, to treat velvet, follow these steps:

First, you should raise the temperature. Generally, the parasite that causes velvet will die in hotter temperatures. Thus, whilst you’re treating your betta increase the temperature to between 82-85°F.

Also, ensure you don’t raise the temperature too quickly. Or you risk killing your betta fish through shock. Instead, slowly increase the temperature by 1°F every 24 hours.

Simultaneously, you should also dim your tank the whole time you’re treating your betta fish. Likewise, the parasite that causes velvet has chlorophyll in its cells. Thus, it can use photosynthesis.

Also, you should add aquarium salt to your tank. Also, once again, add salt slowly. Thus, take some water out of your tank and dissolve the salt in it, before adding it back in.

Lastly, you should add 1 teaspoon of salt for every gallon of water in your fish tank. Particularly, you should add the salt over a 3-4 hour period so you don’t shock your fish.

Severe Cases

Particularly, in more severe cases of velvet, you’ll need to use stronger medication. Thus, the main two are copper and malachite green. Therefore, if you plan on using these methods, regardless of whether there are other fish or plants in the tank or not, you should use a quarantine tank.

Copper For Velvet

For best results, you are to follow the instructions that come with the medicine. However, there are a few things you should always remember.

Accordingly, you can choose between using

  • copper sulfate or
  • chelated copper

Meanwhile, copper sulfate is more effective. However, it can be very hard to keep the right level of copper sulfate in the tank as it dissipates quickly.

On the other hand, chelated copper is much more stable. However, some people think it isn’t as effective. Most people prefer to use copper sulfate. However, if you’re not comfortable with the higher risk then stick to chelated copper.

Likewise, it’s important to note that you shouldn’t use copper if your aquarium’s pH is too low. You know betta fish like a pH around 7 but sometimes it drops.

Thus, if the pH drops below 6.4, then using copper is extremely dangerous. Also, below 6.4 copper will begin killing the bacteria that remove

  • ammonia and
  • nitrates from the water.

Thus, you should only use copper on fish. And not on any other living things in your tank, including plants.

Hence, that’s why it’s so important to move your betta to a quarantine tank. Meanwhile, copper is especially deadly against invertebrates.

Malachite Green For Velvet in Betta Fish

Along with copper, you might consider using malachite green. Once again, different manufacturers of malachite green will have different recommendations that you are to follow. Likewise, malachite green will stain things in your tank. Thus, you should only use it in a quarantine tank.

Also, remember, even if velvet seems to be clearing up, make sure you treat your fish for the recommended number of days. This is because Oödinium could still be living in the water or inside your fish.

How Long Will it Take to Treat Velvet in Betta Fish?

In general, Oödinium will only last 2 days in water without finding a new host. However, if it does find a new host it will live for 2 weeks. Thus, to make sure you eradicated all traces from your tank it will take 3-4 weeks on average.

What Causes Velvet In Betta Fish?

You are already aware that a parasite called Oödinium causes velvet. However, it’s good to be aware of what conditions it thrives in. Also, as an interesting side note, did you know that Oödinium is sometimes classed as algae. This is because it contains chlorophyll.

Either way, it’s something you don’t want in your betta tank.
Thus, here are some common causes.

New unquarantined fish – If you’ve added betta fish to your tank straight away without quarantining them, they may be harboring Oödinium. Meanwhile, this is one of the reasons it’s so important to quarantine fish for 4 weeks before adding them to your main tank.

New plants – Particularly, sometimes, adding new plants can introduce the parasite as well. Hence, if you plan on adding new plants, you should disinfect them beforehand.

Old water – Often, the older your water is, the more time Oödinium has to breed and spread. Therefore, this makes it more likely to infect your betta fish.

Also, you should be changing your water regularly. Likewise, depending on the size of your tank it could be every 2-3 days or every week. Also, remember to use a filter as well.

A drastic change in temperature – Generally, a change in temperature could not only cause a bloom of the parasite to grow but it’s also going to affect your bettas’ immune system.

Lastly, if your betta fish fatigues, unhappy, or stressed then they’re more likely to get velvet. This is because their immune system is going to be compromised.

How to Prevent Velvet in Betta Fish

Usually, to prevent velvet, the key is to lessen the causes as much as possible. Thus, now that you know all the main reasons, it’s your job to keep everything in check. Also, make sure your betta stays healthy and strong.

Therefore, a few things you can do are.

Make sure your betta fish has a nutritionally complete diet. Generally, bettas are meat-eaters. Thus, make sure you’re giving them plenty of meat.


  • bloodworms,
  • daphnia,
  • mosquito larvae, and
  • brine shrimp are all great in combination with high-quality betta pellets.

Also, live food is even better for them, as it makes them work more for it.

Likewise, you should be monitoring your water. Therefore, make sure that you’re checking the pH and temperature as well as the other water parameters. Thus, if anything is out of sync then you must take the appropriate action to fix it.

Avoid stressing your betta fish out. For example, if you notice him flaring a lot, then he may be seeing his own reflection. Also, constant flaring causes stress and can increase the chance of catching velvet.

Is Velvet Fatal?

Ordinarily, velvet is an easy disease to treat when caught early enough. Also, when you take the appropriate action. However, if you leave it unchecked, velvet can quickly become fatal.

Usually, velvet starts in the gills of fish. Particularly, this is where it infects the cells before eating them. Thus, if this goes on for long enough, respiratory failure will occur in your betta and he’ll die.

How Contagious Is Velvet in Betta Fish?

Generally, velvet is extremely contagious. Thus, if you have other fish in your tank you’ll need to remove your betta immediately to stop the spread. And to even make matters worse, when the protozoa are looking for a new host to infect, they won’t be visible in the tank. Thus, you won’t be aware they are there.

The Life Cycle of  Oödinium

Particularly, there are four stages that Oödinium goes through in its life cycle.

First, it feeds. This is when it first infects your betta fish. Therefore, it will begin eating the cells it has infected as well as photosynthesizing using any light available.

However, the second stage occurs when the parasite has matured enough. Similarly, it will eat its way out of the skin and float freely in the water.

Next, the parasite will start reproducing by dividing itself. Meanwhile, the second and third stages are the stages where the parasite is most likely to die. This is because they can only last a couple of days in this state without a host.

Lastly, they will search for a new host to infect.


  • First, velvet is caused by parasites in the water. Also, which need light and stable temperature to survive.
  • Also, in the early stages of infection, you may notice your betta rubbing against things before gold dust appears over their skin.
  • Particularly, as velvet progresses common signs to be aware of clamped fins, bulging eyes, and so on.
  • Also, the treatment of velvet will take 3-4 weeks.
  • Velvet can be caused by poor water parameters, and so on.
  • Likewise, it’s contagious. Meanwhile, if you have more than one fish, the infected one should be quarantined immediately.
  • Lastly, velvet is easy to treat. Nevertheless, it is fatal if you leave it unchecked

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