This page is part of our betta disease and illness section.

We also have a handy Betta Illness Photo Guide that we send out to members of our email list. The guide includes the key points about betta illness and extra photos of symptoms.

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What is Velvet?

To put it simply, Velvet is a parasite infection. It can be one (or more) of several parasites known as piscinoodinium. The main way a betta can become exposed to the parasite is when a fish with the infection is added to the aquarium. Velvet is very contagious so it can spread quickly to other fish. It can also hitchhike on things like plants, previously used aquarium décor or other aquarium inhabitants like shrimp or snails.


  • The main sign of Velvet is a yellow or gold-like dust covering a betta, which will be easier to see if you shine a light onto the fish.
  • If your betta is suffering from Velvet, it may start rubbing itself against items in the aquarium.
  • General reactions to illness will also occur, such as a loss of colour, loss of appetite, lethargy and clamped fins.

Possible Cures for Velvet

Usually it’s good practice to isolate an infected fish before treatment if your betta isn’t the only inhabitant of its aquarium. However, this doesn’t apply with Velvet because you need to remove the disease whilst it’s in the water, not remove it from the betta. You’re treating the entire aquarium for Velvet, not just the fish itself.

If caught in its early phases, betta Velvet is easy to cure. It’s always a good idea to keep a look out for it. The longer Velvet goes without being treated, the more harmful and stressful it will be for your betta. If it goes untreated for too long the betta may die, but for this to happen the fish would need to be living in poor conditions and you would need to neglect the disease for a long time.

The medication mentioned below is most effective when the Velvet is in it’s free-swimming stage. During the other stages the disease will be somewhat resistant to medication.

However, you don’t need to worry about targeting Velvet at a particular stage, you just need to start treating it as soon as you notice it, and continue the treatment until you can be sure the disease is gone.

If you are interested in knowing more about the lifecycle of Velvet and how the illness grows in the aquarium, there’s a detailed guide here from Fish Channel.

As well as medication, it’s a good idea to add salt to the aquarium when treating your betta for Velvet; this should help to get rid of the disease more quickly (1 teaspoon of aquarium salt per 2 1/2 gallons of water).

Steps to treat Velvet

1. Raise the temperature of the aquarium by a few degrees so it sits at about 85°F (Velvet is very temperature sensitive, the warmer the water, the greater your chances of curing it.).. If you are keeping your fish in a small aquarium (15L or less), move it to a larger aquarium (we recommend 20L+) and set the temperature accordingly. A stable temperature is needed to cure any illness. The smaller the body of water, the more the temperature can fluctuate. A larger body of water with a heater set to 85 is more likely to stay at 85 at maximum warm-up. If you do move your betta to a hospital aquarium for treatment, it’s a good idea to treat BOTH aquariums in order to ensure the display  aquarium is free of Velvet. It would be pointless curing your betta and then putting it back into an aquarium still infected with Velvet – all the hard work would be lost.

2. If you plan on medicating the betta’s original aquarium, we recommend you do an 80% water change before adding any treatment to the water. Remember to remove any chemical media (such as carbon) from the filter as this will remove any medication from the water, rendering it useless. Depending on the severity of the illness, you may wish to use aquarium salt to cure your fish. Salt, if used properly (see our guide here), is a great cure for Velvet.

3. Start by adding the selected medication (we have included some recommendations below) to the aquarium. The dosage will be specified on the medication packaging (it’s usually measured in drops per gallon). If after 5 days there appears to be no sign of the Velvet disappearing then add salt as well as the medication.

4. Continue to medicate until all visible signs of Velvet have disappeared. Once you notice that the Velvet has cleared up, we recommend that you continue medication for another 48 to 72 hours (provided that your betta is the only critter in the tank) to ensure that the parasites have been completely removed from the aquarium . We cover this in more detail below.

Continue aquarium maintenance as normal

Whilst medicating for Velvet, you should continue your routine of maintenance and water changes as normal, but re-medicate the aquarium accordingly after each water change. Also, when your betta is cured and healthy, do a  60% water change to remove any excess medication. You should remove any carbon from your filter before medicating (as carbon will remove medication from the water) so simply re-insert it into the filter once the treatment is complete. This will help to remove the medication from the water. HOWEVER, this will not remove salt. If you’ve added salt to the aquarium to cure your betta, it will gradually be removed as you continue to do water changes. There’s no rush to get all the salt out at once, a small amount lingering in the aquarium will be harmless to a betta.

Monthly water changes will eventually remove all the salt, but if you end up doing a full clean out of your aquarium (100% water change), this will ensure that any salt has been removed from the water.

Medication / Chemicals For Velvet Treatment

Malachite Green has been known to work effectively when it comes to curing Velvet. Malachite Green is very strong as far as betta medication goes. If you follow the instructions clearly (usually given on the bottle) it should be fine, but do not overmedicate, it will kill your betta.

The medication will affect each fish differently. There are lots of variables to consider, like the size of the aquarium and the fish’s age.

Copper sulphate is often used to treat Velvet as well, but it is very toxic, so use with care. Instructions for use will be given on the bottle.

Medication that Uses Malachite Green

Malachite Green by Kordon

Medication that Uses Copper / Copper Sulphate

Mardel CopperSafe by Fritz Aquatics

Aquarium Salt

Aquarium Salt by API

Using salt to Medicate

Adding salt to your aquarium can be a great method of getting rid of velvet, but like medication, should always be approached carefully – we recommend you read about salt implementation here before following our instructions below. We recommend salt dosages below, but these should only be used as a reference. Depending on how you source your treatment salt, dosage instructions may be given on the product box/packaging.

For velvet we recommend dosing about 22 grams per litre of the aquarium, but, as mentioned above, you should also consult any available instructions.

Is salt still ok if the betta isn’t alone in the aquarium?

Velvet is highly contagious, so you need to treat the entire aquarium for it, not just your betta. However, while salt is great for curing bettas, it is not suitable for all aquarium dwellers. If your betta is with plants and animals that can also cope with salt, great! You can add salt to your aquarium as described. If not, then you have two options:

  • Medicate the aquarium without salt. This is possible, but may mean that it takes longer to cure the aquarium.
  • Medicate separately. You can medicate your normal aquarium without salt, and transfer the betta (and any other salt-resistant critters) to a hospital aquarium and medicate that with salt. Remember, if the betta is cured first, do not reintroduce it to the ‘home aquarium’ until it has also been treated.

I’ve cured Velvet but it keeps coming back

Many fish keepers can be frustrated with this illness as it can seemingly keep coming back, when actually it just hadn’t completely gone in the first place.

When you treat your aquarium for Velvet, you should not assume the disease has been entirely removed once your betta starts to look healthy again. Due to the life cycle of Velvet, it can still exist in the aquarium even though it’s not ‘attached’ to your fish. Even if it’s not physically affecting your fish, it can still be somewhat ‘growing’ in the aquarium. You need to ensure that Velvet is removed from the aquarium water, not just from the betta.

With bettas being a tropical species, you shouldn’t need to medicate the aquarium for too long. Velvet is vulnerable at a higher temperatures, so this makes it quicker to cure in a betta aquarium than it would in a cold water aquarium. You shouldn’t need to medicate for Velvet for longer than 10 days.

Provided that the betta is the only critter in the tank, we recommend medicating for an extra 48 to 72 hours once it looks like the velvet has disappeared on your betta .