What is velvet disease in betta fish?

In this article we will discuss velvet disease on betta fish.This article describes how to diagnose betta velvet, how to treat it, and how to prevent it.


In this blog

  • What is velvet disease in betta fish?
  • What are the causes of velvet disease in bettas?
  • What are the symptoms of velvet disease on betta fish
  • How to treat velvet disease on betta fish?
  • How to prevent velvet disease on betta fish?
  • How long does velvet treatment take?
  • Summary 
  • Frequently asked questions
  • Reference 

What is velvet disease in betta fish?

Velvet disease, also called gold-dust, rust and coral disease, is a fish disease caused by dinoflagellate parasites in freshwater fish. The disease gives infected bettas a dusty, brownish-gold color. 

These unicellular organisms invade the slime coat of betta fish and begin eating in their cells.It has been found in saltwater aquariums but more commonly affects freshwater aquariums.

The film may be hard to see, but it’s easier to detect by pointing the flashlight beam at the fish in a dark room. Parasites are most commonly visible on fins and gills. 

What are the causes of velvet disease in bettas?

If you add the fish to the aquarium immediately without isolating it, it may be inhabited by velvet parasites. This is one of the reasons why it is important to isolate fish for 16-21 days before adding them to the main aquarium.

Adding new plants can also introduce velvet parasites. If you plan to add new plants, you need to disinfect them in advance.

The older the water in the betta aquarium, the longer it will take for the betta parasites to propagate and spread.This makes your betta more likely to get infected.

Not only can a change in temperature cause the parasite to flourish, it also affects your betta immune system.

If the bettas are tired, unhappy, or stressed, they are more likely to get a velvet. Because their immune system is at risk.

Do not stress your betta fish. Constant flaring causes stress & can even increase the chance of catching velvet. 

What are the symptoms of velvet disease on betta fish?

As a betta owner, you need to know what to look out for in order to keep your betta fish healthy and happy.

You may not notice the golden coating on the bettas in the early stages. Gold coatings occur because bettas produce excess mucus to fight infection.

Betta Velvet causes symptoms that you can see. This will allow you to cure the Velvet disease before it becomes deadly.

Betta fish will scratch its body against hard objects

Betta fish will rub their bodies on anything in the tank. This is because the parasite irritates them. By rubbing their body against objects, they are trying to get rid of the parasite.

Other symptoms

  • Betta fish become lethargic or listless.
  • Appetite loss  and weight loss
  • Fast and difficult breathing
  • The fins clamped against the body
  • There is a fine yellow/rusty film on the skin that gives it a velvety look.
  • Bettas start losing their color.
  • In advanced stages, skin peels off.

How to treat velvet disease on betta fish?

Increase the water temperature in bettas aquarium

Increasing the water temperature for betta can also help get rid of velvet disease.

Betta fish work best with water heated to 74-79F.Slowly raising the temperature over 24 hours until the temperature reaches 84 degrees will shorten the lifespan of the parasite.

Velvet-causing parasites die at high temperatures, so keep them warm while treating bettas. Be careful not to raise the temperature too high. 

Otherwise, there is a risk of killing the bettas out of temperature shock.Instead, slowly increase the temperature by 1°F every 24 hours. 

Dim the betta aquarium lights for a few days

Organisms that infect betta with velvet need light. If you leave the aquarium in the dark for six or seven days, the algae in the aquarium water will starve. 

This will not affect the velvet disease already affecting your betta, but will help reduce the number of juvenile parasites.

Add aquarium salt in bettas aquarium

Salt promotes the production of fish mucus, which helps protect your betta from velvet diseases.Adding one to three teaspoons of aquarium salt per gallon of water can help fish that are asymptomatic.

Treat bettas with copper sulfate for ten days

Copper sulfate is the medium of choice. It should be used according to the manufacturer’s instructions for a full ten days to ensure complete eradication of the parasite.

Copper sulfate is very effective, but it quickly dissipates,so maintaining proper levels of copper sulfate in the tank can be difficult.

Do not use copper if the pH of the aquarium is too low. Using copper is very dangerous if the pH is below 6.4.

Cupramine is an excellent copper treatment option for controlling various ectoparasites such as velvet.

Only use copper for fish and not for other organisms (including plants) in the aquarium. So it is very important to get the bettas into the quarantine tank. Copper is particularly deadly to invertebrates.

Treat bettas with malachite green

Also consider using malachite green. Again, different manufacturers of malachite green have different recommendations to follow. Malachite green also pollutes things in the tank, so use it only in quarantine tanks.

Discontinue carbon filtration in bettas aquarium during treatment

Remember to remove carbon from your filter system when you use the treatment in your aquarium. 

Carbon absorbs your medicine and either reduces its effectiveness or completely eliminates it from the water column.

How to prevent velvet disease on betta fish?

Being aware of the symptoms should give you a good idea of ​​whether your betta is suffering from velvet. If you think it’s velvet, follow the steps below.

Velvet disease is curable, and if you follow the instructions below, your betta fish has a good chance of surviving.

Isolate/quarantine new fish before adding them to bettas aquarium

If you introduce a betta fish or any other fish with velvet disease, it will infect the water column and other aquarium companions. Isolate new fish for two weeks before adding them to the aquarium.

Change the betta aquarium water frequently

Frequent water changes can prevent the accumulation of unhealthy pollutants such as betta velvet & regular water changes bring fresh water into the water column and keep the area around your fish clean.

It also removes contaminants that reduce your pet’s ability to fight off a betta velvet.

Test the betta aquarium water

With a good water quality test kit, you can look up some parameters such as pH, ammonia, nitrates and nitrates. You can adjust the water condition to keep your bettas healthy.

Do not overcrowd the bettas aquarium

If you keep bettas in a community aquarium, make sure you don’t put too many fish in the aquarium. Many fish can stress your betta fish, and that stress can make them susceptible to diseases like velvet disease.Avoid overstocking their aquarium.

Feed bettas correctly and properly

Remember to give your betta just enough food to be able to eat in just a few minutes. Feeding a healthy diet that contains more nutrients than fillers also helps prevent betta velvet from affecting your fish.

Blood worms, water fleas, mosquito larvae and brine shrimp work well in combination with premium betta granules. Live food is even better for them. 

How long does velvet treatment take?

The velvet parasite will survive in the water for only 2 days without finding a new host. But if he finds a new host, he will live for 2 weeks. 

So, it will take 3-4 weeks on average to make sure you have eradicated all traces from your aquarium.


The velvet disease can make your betta fish listless, and you will notice that it does not move around the aquarium and tends to stay hidden.

Velvet disease is highly contagious, and once your betta tank is infected, it can be difficult to treat.

Lethargy and loss of appetite are also signs of velvet disease. As your fish get sick,they will weaken. When weakened, they become lethargic and lose their appetite.

Quarantine new fish for two weeks and don’t overcrowd your bettas tank or don’t overfeed your betta fish.

Early detection of symptoms of betta velvet, including discoloration, pinched fins, rapid breathing, and scratching.

A major water change will remove many of the parasites suspended in the water column.

Betta velvet should be treated as soon as possible by dimming the light, raising the water temperature, adding aquarium salt and treating with medicines.

The earlier you treat velvet disease, the more likely your betta fish will survive.

Frequently asked questions

Is betta velvet disease contagious?

Yes, it’s contagious and can be difficult to treat if a betta tank is infected.

Is betta velvet a bacterial disease?

Betta velvet is not a bacterium or virus, but it is a unicellular parasite that can infest the water in a betta tank. Understanding the condition helps prevent and treat it early.

What are the other names for velvet disease?

Velvet disease is also known as gold-dust, rust and coral disease.

Is betta velvet disease curable?

Yes, betta velvet disease is curable if caught early.