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How To Treat Blue Tang Stress Spots!

As the number of people keeping blue tang in their aquariums continues to increase, we constantly see more and more people reaching out with various questions about keeping blue tang and more importantly, making sure that they are happy and healthy.

Although blue tang is a great fish to keep in your aquarium, they can be skittish and easy to scare and stress with anxiety being common in the species while also being more susceptible to parasite infections such as ich too.

This can make blue tang more difficult to care for than most people initially realize with many people, unfortunately, ending up with problems with their fish.

We already have a dedicated article going over how to treat blue tang with ich due to it being more difficult to treat in blue tang due to their skittish nature but we have noticed more and more people reaching out and asking about blue tang stress spots.

Our hope is that our article will be able to help people better understand stress spots on blue tang as they are commonly confused with an ich outbreak with some people even saying that stress spots on blue tang are not even real.

We will be covering the three most common questions that we see from the community about blue tang stress spots and our table of contents below should make the article as easy as possible to navigate.

How Do You Tell If A Blue Tang Is Stressed?

The most common signs of stress in blue tang that can result in stress spots is subdued colors on the fish, a faded pattern on the fish, obvious insecurity in its surroundings including increased levels of aggression to its tank mates, and a loss of appetite.

If stress levels in the blue tang are not normalized within a couple of days, stress spots will often start to form within a week or so.

The most common reasons that a blue tang will end up being stressed are poor water parameters, an overstocked tank, and aggression from its tank mates.

Ich and velvet breakouts can also make a blue tang stressed or anxious too and this is one of the common reasons that ich and stress spots in blue tang are commonly confused with each other due to both being present at the same time.

It does tend to be rare that a blue tangs tank mates will be overly aggressive towards it and you will often see the other fish nipping and chasing the blue tang making it easy to find the culprit.

A common species that will be aggressive towards your blue tang is a clownfish and many people presume that they are a calm fish but we have published multiple articles relating to clownfish aggression now as many new fish keepers are unaware of just how aggressive they can be.

“Blue Tang Fish” by Victor Wong (sfe-co2) is licensed under CC BY-NC-SA 2.0. To view a copy of this license, visit

How To Treat Blue Tang Stress Spots!

You are not able to directly treat stress spots in blue tang as they have to naturally fade as the stress and anxiety levels in your blue tang are reduced.

The easiest ways to reduce the stress and anxiety levels in blue tang are to make sure it is in water that is within suitable parameters, make sure it is free from ich, and check for signs of other fish in the tank being aggressive towards the fish.

Having your blue tang in an overstocked tank can be a problem as the only way to reduce the stress levels is to reduce the number of fish in the aquarium or to upgrade to a larger tank.

Another common issue is that people will keep their blue tang in a tank that is far too small for them with the majority of people recommending that a pacific blue tang has an aquarium of 100 gallons.

The majority of people think that a 100 gallon aquarium is out of their price bracket but you are usually able to find pre-owned 100 gallon tanks on eBay for a fraction of their normal price.

Due to the pacific blue tang being such an active species, being in a small tank can be enough to cause it to break out in stress spots and start to act aggressively towards its tank mates so upgrading to a suitable tank size can be enough to reduce the stress levels in your fish.

Are Stress Spots Real On Blue Tang?

Stress spots are a real issue for all types of tang but they are very commonly misidentified as ich due to ich being a common cause of stress spots in blue tang.

There are other causes of high stress and anxiety in blue tang that will cause stress spots to breakout though without ich or other parasite or bacterial infections being present on the fish.

This can make it problematic to correctly treat stress spots on blue tang as many people on social media instantly presume that the stress spots on the fish are simply a sign of ich breaking out and recommend an ich treatment but this is not correct.

You have to try and identify the specific cause that is stressing your blue tang out and look to treat it to get the stress spots to fade as quickly as possible.

Thankfully though, you are usually able to identify and treat the cause of the increased stress levels in your blue tang using the methods covered earlier in the article.

Once you have worked on removing the cause of the stress, the actual stress spots on your fish can fade just as quickly as they appeared with the faded color and pattern of the fish usually returning to normal just as quickly too.


That brings our article going over dealing with blue tang stress spots to an end. We hope that we have been able to help our readers better identify the potential causes of the issues in their fish as well as how to fix them. Many of the common causes of stress in blue tang are easy to fix but if the problem is due to the fish being in an overstock tank or a tank that is too small for it then you may have to spend money to fix the problem by upgrading to a new tank for your blue tang.