Why is My Betta Fish Turning White?

Why is My Betta Fish Turning White?

Betta fish are well known for their magnificent coloration. However, they sometimes lose their gorgeous blue or red or green or other coloration and it fades to white. What does this mean? Is it deadly?

If your betta fish turns to white, it could be an indication of several diseases including some deadly ones. However, it could also be a normal part of your betta’s growth. It is important to closely examine and watch your betta in order to determine whether or not it is harmful.

In this article, we will cover the marble gene, stress, body flukes, Ich, body rot, columnaris, lymphocytes, slime coat shedding, and costia.

Marble Gene

The marble gene is a specific gene that can control a betta’s coloration throughout its life. In other words, it can cause random color changes even after betta is several years old and the factors that trigger the gene are unknown.

This gene can turn gorgeous betta into a mottled mutt, but it can turn very plain betta into a magnificent one. The color changes may stop after the first incident, but a betta could also experience constant color changes throughout its life.

Most of the time betta will marble into a darker color, but it is possible to marble into a lighter one. The change normally spreads scale to scale and takes anywhere from a few days to a month to complete a change.

This is a non-harmful option for your betta’s color change. If just a few scales are turning white, it is possible that your betta has the marble gene. If the change continues to progress, especially if other colors become a part of the change, it is probably simple marbling.


Stress has a significant impact on the health of a fish. When severely stressed, bettas lose their coloration and start to exhibit horizontal stripes often referred to as “stress stripes”. If your betta is already a lighter color, stress may turn it white.

In addition, if your fish is ready to breed, it may have verticals barred stripes. These are much larger than the horizontal stress stripes, but the stripes alternate light and dark, and in light colored bettas, the lighter stripes could appear white.

Firstly, if your fish is experiencing paleness all over the body and horizontal stripes is to reduce the stress that your betta is going through. For instance, make sure that it’s tank mates are not attacking it, it can’t see its reflection, the flow is not too strong, the temperature is between 78-80 degrees, there is not any ammonia or nitrite, and nitrates are not over 20ppm.

Body Flukes

A fluke is a type of parasite commonly found in aquarium water. Healthy fish have strong enough immune systems to fight off most of these, but if they become stressed or the water quality plummets, fluke populations can rise and infect your fish.

Body flukes are white in color and you can normally see them with the naked eye. They are several millimeters in length and very thin. If there are too many of them, it may just look like your betta is turning white.

These are normally very treatable with anti-parasitic medications. Praziquantel is a great medication for this and is found in several medications, most notably Prazi-Pro and API General Cure.


Ich is an unfortunately common parasite found in fish. It spreads easily and has a relatively long life span, meaning treatment needs to last for at least a month as the young cysts can hide in the substrate for long periods.

The good thing about Ich being common is that every pet store that sells fish will also sell Ich medication. Ich is also easy to identify as it looks like white dots all over the fish. If your betta looks like someone rolled it in salt, it has Ich.

Body Rot

Body rot is an unfortunate side effect of fin rot if the fin rot is either extremely aggressive or if it goes far too long without treatment. In most cases, body rot happens after the fin has been rotted away entirely and the rot moves to the body.

Fin rot is common in betta fish with long fins because their fins are so long that circulation to the edges is often poor. This can lead to flesh rotting and becoming infected with both bacteria and fungus.

The best medication to treat fin rot is Methylene Blue. This is also helpful for body rot infections as it treats external bacterial and fungal infections. However, if fin rot went on long enough for it to reach the body, chances of survival are not good.

The other way to get body rot is an extremely aggressive form of fin rot. Most fin rot spreads as it progresses in a straight line and only progresses after rotting away some of the fin. However, aggressive forms of fin rot can jump from one part of the body to the other.

It can jump from the edges of the fins to the middle to the body and can cause white lesions that resemble marbling. Initially, it does not appear to cause any damage to the body, but over time it will eat away at the skin. Methylene blue dips and baths should be used along with strong antibacterial medications such as Kanaplex.


Columnaris is an extremely aggressive bacterial infection that resembles a fungus. If you see a fluffy white patch on your betta, it’s probably columnaris. This infection kills fish in 12-96 hours, depending on the strain.

Some fish will show symptoms of this disease while others will die quickly and without symptoms. The best way to treat it is a combination of Furan 2 and Kanaplex or with Maracyn. This disease is normally brought in by unquarantined tanks and is not seen in tanks where the fish were properly quarantined.


This is a very uncommon viral disease that currently has no cure. It looks like lumps coming out of the fish and can occur anywhere on the fish. If one fish is exhibiting symptoms, it must be isolated from other fish as it is contagious.

The lumps are normally either pink or white and the average person may confuse them with Ich, though they tend to be much larger, abnormally shaped, and there are fewer lumps on the body than with Ich. Sometimes a fish will go into remission on its own but is possible for the lump to reappear.

Slime Coat Shedding

If a fish begins to shed its slime coat, it will appear cloudy and white either in patches of the body or all over the body. The production of excess slime coat will also have similar symptoms and causes.

This is not something that you can treat for with medication, but it is normally caused by an irritant in the water. The most common one is salt. If you added salt to treat any abnormality, normally fin rot, it can have adverse effects on the overall health of the fish.

Other toxins in the water can also cause this effect, such as certain aerosols, soaps, lotions, or other chemical products that may have entered the water. Normally, several large water changes upwards of 50% will help this affliction.


Costia is a parasite that looks very similar to slime coat shedding. It is too small for the naked eye to see and can only be positively identified using a microscope. Costia is a rarer parasite that is not normally seen in tropical fish, but it is good to be aware of all possibilities.

There are not many medications specifically for Costia, but most Ich medications will work on this parasite because the two parasites are similar. This would definitely make the betta look white all over, or at least extremely cloudy.

In conclusion, there are several different diseases that can make a part, or all, of a betta white. Luckily, they are normally easy to treat and have several medications available for each of them. In addition, the marbling gene is entirely harmless but can turn bettas white.

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