Betta Fish Velvet Disease: Symptoms, Cause & Treatment

Maintaining our Betta’s health is more than just giving them good-quality food and doing regular water changes. We must also be able to gauge their health at all times. 

How do we do this?

We know and understand the common ailments that Betta fish can get, so we can be on the lookout for them, then treat accordingly.

In this post, we will take a hard look at Betta fish velvet disease, its symptoms, cause, and treatments.

velvet disease


What is Betta Fish Velvet Disease?

Also known as Coral Disease, Rust, and Gold Dust Disease, velvet is caused by small parasites found in the algae of your aquarium. Oodinium is a single cell organism with a three-stage life cycle;

  1. Tomont: starts as a single cell, resting on the substrate and decorations in your tank. It reproduces by fission (a process where the cell divides into an identical cell). Each individual cell can replicate itself up to 256 times!
  2. Juvenile: as these cells mature they turn into juveniles that are capable of moving. They will do so, moving from the floor of the tank and decorations to the water itself. Once here, they look for a host (a.k.a your Betta).
  3. Adolescent: once this parasite can attach to a host, they move into the adolescent stage. From here this parasite will penetrate the Betta’s slime coating and will begin to feed on his cells. This produces the appearance of gold dust or rust. 

Symptoms of Betta Fish Velvet Disease

Betta fish velvet disease does produce visible symptoms. Here’s what to be on the lookout for;

  • Loss of natural color
  • An appearance of rust or yellow-colored film on body
  • Labored breathing (fish appears to be gasping or breaths are coming in irregular intervals).
  • Clamped fins (the ventral fins will be parallel with the Betta’s body, while the anal and dorsal fins will be closed tight). 
  • Loss of appetite (is not interested in food, which will lead to a weakened immune system).
  • Legarthy (hides more or stays at the bottom of the tank).
  • Scratching or rubbing up against objects and substrate (this parasite makes the fish itchy and agitated, so it seeks relief by rubbing itself on objects). 
  • Peeling skin (the scales will begin to fall off).

Males are more noticeable when they develop velvet because of the loss of natural vibrancy (whereas females are normally dull). However, the tell-tale sign of velvet is the spots, dots, or overall film spreading on your fish’s body and fins. 

Without immediate treatment, your Betta may experience even further symptoms like peeling skin, labored breathing, clamped fins, and finally, death. 

Treatment of Betta Fish Velvet Disease

If you suspect your Betta has velvet disease, follow these tips to help get him on the road to recovery.

Change the Water 

The first thing you will want to do is a large water change. This will clear out the parasites when they are in the tomont and juvenile stages (before they attach themselves to your Betta). A significant water change will also help clean up any pollutants that will affect your Betta’s ability to fight disease.

Turn Up the Heat 

Bettas do best at temperatures between 75 and 80 degrees Fahrenheit. However, to help fight this parasite, you will want to slowly (over 24 hours) raise the aquarium temperature to 85 degrees Fahrenheit. This will shorten the lifespan of the parasites. 

Turn Off the Light

Since these parasites are found in algae, turning off the light source for seven days will starve the algae and, in turn, will help reduce the number of juvenile parasites.

Note: the darkness will not affect those parasites already on your Betta fish.

Betta Fish Chemical Treatments

If your Betta fish has an extreme case of velvet disease, the above methods may need some further assistance in curing this illness in the form of chemical treatments. 

Aquarium Salt 

Aquarium salt may be effective when treating velvet because it dehydrates the parasites, shortening their lifespan. However, you will want to start slowly when using this chemical treatment.

First Salt Treatment

Use 1 tablespoon of aquarium salt for every 3 gallons of water.

Dissolve the total amount of salt in a cup of your tank’s water. Pour it into your aquarium. 

This small dose can be very effective in treating velvet (if caught early). The low-dose salt will also stimulate the production of the beneficial mucus that covers Betta’s body, which will make it more difficult for parasites to enter.

Let your Betta sit in this concentration for at least 4 days. If there is no improvement, move on to the second treatment.

Second Salt Treatment

Use 1 tablespoon of aquarium salt for every 2 gallons of water.

If after 10 days there’s still no improvement, move on to the third dose.

Third Salt Treatment

Use 1 tablespoon of salt for every gallon of water.

This is a very aggressive dosage and is not recommended for tanks with live plants, invertebrates like snails, or scaleless fish species.

Important Tip: As you increase the dosage of aquarium salt, you must perform water changes in between treatments. Since salt is not affected by a filtration system and will not evaporate from the water, you run the risk of overdosing your Betta without clearing some of it out. 

For example, a 10-gallon tank second treatment requires 5 tablespoons of salt. If you take out 20% of the water, you will need to replace 1 tablespoon of salt with fresh water to meet that ratio. 

Continue salt treatments until your Betta appears healthy again. At this time, you will want to take out 30% of the water and replace it with unsalted fresh water. Watch your Betta for a week. If all is well, do another 30% water change. 

If the velvet returns, you may want to consider another treatment plan.

Copper Sulfate 

This is a longtime method for treating velvet in fish. Products that contain copper sulfate are available through your pet retailer or online. Be sure to follow the manufacturer’s guidelines and remove the carbon portion of your filter (carbon deactivates the copper sulfate).

Betta Velvet Commercial Treatments

If you want to skip the “home remedies” for treating velvet, there are plenty of commercial medications on the market that may do the trick. Ask your fish retailer for products they carry to aid in the treatment of velvet in Betta fish. 

Prevention of Betta Fish Velvet Disease

It’s always best to prevent an ailment, rather than deal with it after it has infected your fish. The prevention is not difficult or time-consuming. Just follow these tips.

Tip #1 – Quarantine New Tankmates 

Since velvet disease is highly contagious, always quarantine any new additions to your tank for at least 14 days. During this time watch for any signs of fungus, parasites, or bacterial diseases. 

Tip #2 – Proper Feeding 

Always choose a high-quality diet for your Betta fish. This will help build a strong immune system, which, in turn, will help your fish fight off sickness. In addition, never overfeed your fish. This only pollutes the water with uneaten, rotten food and fish waste.

Tip #3 – Tank Maintenance 

Velvet and other parasites thrive in poor water quality. Be sure to do regular water changes (with a gravel vacuum) and change the filter media when it is no longer able to keep the water clean. 

Tip #4 – No Overcrowding 

If your Betta is good-natured and doesn’t mind having tankmates, it may be tempting to give him lots of company. This is not a good idea. Too many fish in one habitat can cause stress for even the nicest of Bettas. Stress can then lead to all kinds of ailments, not just velvet.

Tip #5 – Test the Water

Making sure your Betta’s tank is maintained properly also means testing the water. Check the parameters for pH (between 6.8 and 7.5), ammonia (0), nitrate (under 20 ppm), and nitrites (0).

If your levels are not right, do a partial water change, then add commercial products to help get your tank back into the safe zone. 

Final Thoughts on Betta Fish Velvet Disease

Betta velvet disease is preventable. Be sure to maintain the tank, feed your fish a high-quality diet (but not too much), and avoid overcrowding. 

However, if your fish does get velvet, it doesn’t have to be fatal. 

Treat your Betta ASAP by raising the temperature in the tank, turning off the light, and adding either home remedies or commercial velvet medications.

Once your Betta is back to himself, return the tank to its normal state and keep a watchful eye to ensure it never happens again.