Betta Fish Losing Scales – Typical Causes and Solutions

betta fish losing scales

Betta fish (Betta splendens) are perhaps one of the most popular aquarium fishes, and for a good reason. They’re attractive, relatively easy to care for, and have a reputation for being quite personable.

As a betta fish owner, you may at some point become concerned with your betta fish losing scales. Betta fish generally don’t shed scales, so you may have good reason to be concerned if you come across this problem.

If your betta fish is losing scales, it is often a sign of ill health. A betta rubbing against objects in the tank may have parasites that it’s trying to dislodge. Redness or other signs of skin damage can be a symptom of illness and will need further investigation. A small amount of scale loss may be natural and not a cause for worry.

Throughout this article, I will discuss several of the most common reasons why betta fish lose scales. Whatever the reason, you will understand what to look for and the available solutions by the end of this article.

Can Fighting Cause a Betta Fish to Lose Scales

Fighting is at the top of this list of why betta fish lose scales, not because it is the most common reason, but because these beautiful fish are renowned (and named) for their aggressive fighting behavior.

Putting two or more Siamese Fighting Fish in a tank together is just asking for trouble, and when these guys fight, scale loss is a strong possibility.

Betta fish have tiny teeth that they use for holding on to food and prey, and when fighting occurs, there can be plenty of fin nipping and fin damage. Bettas will often lose scales in these battles when they try to swim away as another betta has them held by its teeth.

It would be best to only keep male bettas with a small sorority of female betta fish for mating purposes. If you want to give your betta some company, some non-aggressive fish will make good tank mates. Some larger fish can become aggressive toward betta, so it would be wise to research when choosing tank mates.

Do Betta Fish Molt

Betta fish do not molt like some animals. Snakes for instance will shed their skin and some animals will molt their fur usually as the season’s change where they will take on a thicker winter coat or thinner summer coat.

Betta fish, like most fish, do not have a reason to molt so their scales will last them for life if undamaged. Scales that fall off will eventually grow back over several weeks.

Betta Fish Diseases – A Leading Cause of Scale Loss

Many betta fish diseases can cause bettas to lose their scales. These diseases can fall into several categories which are:

1. Bacterial infection

Bacterial infections can be caused by several factors, the most common being poor water quality. Bacteria can enter your betta’s body through a cut or open wound and, if left untreated, will usually cause death. Bacterial infections may appear as redness, irritation, or tiny white spots on your betta’s skin.

2. Fungal infection

Fungal diseases such as fin rot, tail rot, and body rot are pretty common in bettas. Skin that has been suffered damage through bacterial infection can develop a secondary infection such as fungus. This type of fungal infection often looks like white cotton patches or a white fuzz, and it will eat away at the betta’s skin, causing loss of scales and other damage to the fins and tail.

Fungal Infections Fin Rot And Body Rot
This picture shows signs of fin rot with dark and uneven edges around the fin. This fungal infection can also lead to body rot and a potential loss of scales.

3. Parasites

External parasites such as Ich, Flukes, and Anchor Worms will attach to a fish’s body. Internal parasites can cause damage to their gills and may be mistaken for Bacterial Infections. As parasites feed off their host (your betta), they will cause damage to the skin and surrounding tissue, leaving open wounds.

4. Stress

Although not a disease in itself, stress is often the cause of lowered immunity in betta fish, leaving them open to many health problems and leading to more severe infections from relatively low-impact illnesses or diseases.

Many factors can contribute to stress, such as bullying from other tank mates, a tank that is too small (a 5-gallon tank is considered the absolute minimum for a betta), poor water conditions, including dirty water or high pH levels, or even just a new environment.

Often a new environment can mean a new tank setup that has not been cycled adequately before introducing your betta. I have a great guide on setting up a betta tank if you are interested.

Each type of illness listed above can cause your betta to have symptoms such as red, itchy, and generally, unhealthy skin, leading to your betta fish scales falling off, especially from the infected areas.

Itchy skin will often cause your betta fish to flick and rub against rocks or other objects in the tank.

Cause of Disease in a Betta Tank

The cause of illness and disease in betta fish is often from poor water quality or the introduction of infected fish or live plants into a healthy tank.

You can inadvertently introduce parasites through live, infected food, which the parasite uses as its intermediate host. Once consumed, the parasite will reside inside your betta’s stomach or digestive tract and can infect organs where it will feed and multiply.

Many parasites are present in the healthiest fish tank and will not usually be a concern. If water quality diminishes, these parasites will begin to multiply and overwhelm the tank, while at the same time, dirty water can inhibit your betta’s immunity causing the perfect storm.

Bacterial and fungal infections are more prevalent in poor water conditions where uneaten, rotting food waste and a general lack of fish tank maintenance are often the cause.

Poor water quality can lead to increases in Ammonia, Nitrate, and Nitrite levels, killing off good bacteria and lowering oxygen levels in the tank.

Because disease and infections are often linked to a loss of scales, it is essential that you continually monitor the quality of water in your fish tank by using test kits available to buy from your local fish store or pet store. You will need to perform regular water changes, and by using a good quality filter, you will dramatically improve the quality of the water long term.

If you are adding new fish, one good practice I recommend is to use a quarantine tank. This way, you can monitor the new fish for several days, looking for signs of illness before introducing them into the main tank. A disease is not always apparent until symptoms occur several days later.

A dirty unmaintained betta fish tank.
A dirty, unmaintained betta tank is a leading cause of disease and bacteria that can lead to scale loss in betta fish.

Treatments for Disease in a Betta Tank

A quarantine tank is also beneficial when treating sick fish and will help avoid spreading the disease to other fish. Quarantine tanks are also often referred to as hospital tanks.

There are many treatments available that you can purchase in a pet store or specialized fish store. Often the symptoms of an illness will be an obvious indicator of the disease or parasite that is present, making it easier to choose the correct treatment.

If you are finding it difficult to diagnose an illness, I would best advise you to consult a veterinarian or at least somebody that you trust, with enough experience to make a diagnosis.

External treatments such as anti-fungal medicine are often just added to the water, whereas medications that fish must take internally can be added to flake food or pellets.

If the cause of your betta’s scales dropping is due to illness, a quick diagnosis will often result in successful treatment, and the scales will usually grow back within several weeks. Most treatments can take just a few days or several weeks, depending on the severity of the illness.

I cannot stress enough the importance of maintaining a clean tank and monitoring water parameters regularly. Poor maintenance is the most common cause of illness and disease spreading within a fish tank, and it is one of the easiest things to keep under control. You can find a list of all the parameters required for a healthy betta tank in this Betta fish species guide.

If you don’t have a tank cleaning and maintenance schedule already in place, you may benefit from my guides on How often to change betta fish water and How often you should clean a betta tank for optimum health.

Scale Loss Through Injury

One downside for betta fish having such long beautiful fins is that they are often injured when nipped by other fish or rub against sharp objects in the tank. However, injuries are not only limited to their fins, and just like any other fish, their scales are also vulnerable to damage.

Below are a few examples of injuries that could cause your betta to lose scales.

Rubbing Against Sharp Edges or Rough Objects

When setting up your betta tank, it would be wise to avoid sharp objects like rocks and decor. Betta fish are much less likely to injure themselves when in a well-established tank, with no other fish or objects that can hurt them.

You should also consider the type of substrate you will be using. If choosing a gravel substrate, you can opt for a smooth pebble so that if your betta rubs or flicks off the substrate, injury is unlikely.

sharp objects can cause scale loss
The smooth pebble substrate in this image is ideal but the rock has some sharp edges. You would need to judge if your betta is potentially injuring its scales on a sharp-edged object like this and remove it if necessary.

Rubbing against rocks and substrate is common among most fish, although a betta fish with a skin infection or parasite, as I previously stated, may flick frequently and more aggressively in an attempt to knock off the parasite such as a fluke or anchor worm, and this can cause harm to their already delicate scales.

If your betta fish is losing scales and there is no sign of illness, you should monitor them closely to try and establish the exact reason. You may find your betta fish has developed a habit of swimming into tight spots where injury may occur or may be rubbing against an object you didn’t realize was sharp.

Scale Loss from a Heater Burn

Heater burn is also a possibility for skin damage and scale loss. If you find your betta fish is spending a lot of time next to the heater, you will need to check the water temperature in the tank. The ideal temperature range for betta fish is 78° to 80° Fahrenheit or 25.5° – 26.7° Celsius.

If your tank water is too cold, your betta will stay closer to the heater where the water is warmer. Getting too close to the heater for extended periods may cause your betta to burn its skin which may cause scales to drop off. Alternatively, your heater may be too set too high, which will not only be uncomfortable within the tank water, but only a brief encounter with the heating element would cause a burn.

Treatments for Scale Loss in Betta Fish

Injuries that cause scales to drop are not that common, but if you feel that your betta is losing scales due to an injury, you could try adding some Stress Coat by API to the water available at most fish stores or online. Stress Coat works by replacing the natural slimy texture on your fish’s skin which is often lost when injury or illness occurs, and it has added aloe vera, which will aid in the natural healing process.

Other treatments for betta fish injuries are Melafix, Bettafix, Fin and Body Cure, and Pimafix, all made by API Fish Care and available at most pet stores or online. Some of the treatments listed are to treat fungal and bacterial infections; however, they are also helpful in preventing these types of conditions from occurring in open wounds.

Aquarium salt can also be soothing and aid the healing process for skin wounds in fish. You will need to follow the instructions carefully to ensure you add the correct amount to the tank. Bettas are freshwater fish, and too much salt can become toxic for them, causing further irritation or skin damage.


Although a slight loss of scales is quite natural and not usually a cause for concern, you should not ignore it. Betta scales falling off can be caused by many reasons, and you can easily prevent most of them.

Sometimes, loss of scales can be a symptom of more severe health problems, which, left untreated, can often lead to death and/or infection passing to all fish in the same tank.

If you are concerned about your betta dropping its scales and are unsure of the reason, the best advice would be to consult a veterinarian or, at the very least, consult your local fish store for advice.

Jon O'Connell

I have kept both marine and freshwater fish and set up almost 100 aquariums. Happy to share my knowledge and experience to help others enjoy keeping healthy and happy fish.

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