Betta Fish Losing Color (Turning White, Black): What to Do?

Your beautifully betta fish’s colors appear dull, they are turning white or appear pale. What should you do?

A color change for your betta could be something as simple as old age. Conversely, it could be a sign of illness, injury, or a problem with your water parameters. In any case, it is worth your attention.

Siamese fighting fish betta Blue butterfly tail in the planted aquarium

Continue reading for reasons why your fish may be losing its vibrant color and what you can do to help.


High stress is a prime contributor to dulling color. It can cause color changes in your fish as their immune system weakens, making them susceptible to secondary infections.

The following are common causes of high-stress levels in betta fish.

Tank Size

Too small of a tank size can result in significantly elevated stress levels for your betta fish, which will cause their color to fade. While these fish are sold as nano fish that can live in tiny tanks, it is not ideal.

What to Do: Consider a larger tank.

Five gallons is the absolute minimum for a healthy betta. Even better would be a 10-gallon tank, which would have less water parameter fluctuation than a smaller tank.

Tank Mates

Another source of stress and color loss could be your betta’s tank mates. Another male, a fin-nipping fish, or not enough hiding spaces can all contribute.

In addition, if you have paired your betta with fish needing different water parameters, being kept at the edges of these levels can cause long-term harm.

What to Do: Plan your tank layout to include decorations that break up the line of sight and provide sufficient hiding places.

Always pair your betta with fish needing similar water temperatures, pH, and hardness levels.

A New Environment or Immature Tank

Not only is the shipping process stressful for your betta, but the act of transferring them into their new home can cause them stress and result in color change.

What to Do: Always cycle your tank properly before adding your fish as an immature tank brings an elevated risk of ammonia poisoning (discussed more under Water Conditions, below).

Quarantine your fish for two weeks before adding them to the tank and slowly acclimate them using a drip or water transfer method.


Your betta’s color can fade if they are not consistently fed a varied, protein-rich diet.

What to Do: If you want your betta looking their best (in addition to being healthy), spend the extra money for a high-quality betta food.

Supplement with a variety of nutrient-dense live, frozen, or freeze-dried foods, making sure to soak freeze-dried foods before giving them to your fish.

Water Conditions


Your betta can change color due to shifts in water temperature, either hot or cold. These shifts can cause a condition known as temperature shock.

What to Do: Equip your tank with a quality water heater and thermometer to keep the temperature consistent, especially in smaller tanks where the conditions can fluctuate rapidly.

Set your tank away from windows and maintain the temperature between 76 and 80°F (24 to 26°C).

Nitrates, Nitrites, and Ammonia

A healthy home aquarium maintains a balanced nitrogen cycle.

Beneficial bacteria in the tank break down the ammonia produced by fish waste and decaying plants, the nitrite by-product is consumed by another bacteria, resulting in nitrates that can be absorbed by plants and algae or removed during partial water changes.

Unbalanced cycles can result in significant spikes of ammonia, nitrite, or nitrate levels.

Ammonia and nitrite levels should be 0 ppm, and nitrates should be below 20 ppm.

If water conditions are not corrected, your fish could suffer gill or tissue damage, poor blood circulation, shock, or death. Look for red, purple, or brown color around the gills.

Fish with advanced ammonia poisoning may also have red streaks on their bodies or blackened scales.

In addition to a change in their color, look for behavioral changes, such as laying on the tank bottom or gasping at the water surface, heavy or labored breathing, erratic swimming, or curling their head into their tail.

What to Do: Test your water to determine the ammonia, nitrite, and nitrate levels.

Do partial water changes, maintaining temperature and pH level until you reach around 50 percent of the water changed. Test again and repeat the procedure until the levels are under control.

Check and clean your filters to ensure they can remove contaminants. Consider using a water conditioner initially, followed by proper filtration and tank cleaning.


If your betta is injured due to fighting with another fish or from rough contact with the aquarium’s décor, then you may notice their scales or skin turning black.

What to Do: In most cases, the injury will heal itself. Keep an eye on its progress and make sure your water is clean. Dirty water plus an open sore is a recipe for infection.

Life Cycle Changes and Genetics

Your betta may change color due to normal life cycle changes or its genetic makeup. In these cases, there is nothing for you to do but be aware.

If your betta is turning black in the absence of any water parameter issues, dietary concerns, stress, injury, or illness, then it could simply be a natural color change.

Sexual Maturity

As a betta reaches sexual maturity, their colors may change. In most cases, they will darken.

Old Age

A betta fish’s lifespan is from three to five years. If they are getting older, it is not unusual for their color to fade.

Their bodies will naturally not produce as much pigment as when they were younger.


Some betta fish variations, such as the marble betta, naturally change color over their lifetime and can even change color depending on their mood.

In addition, certain genes increase the amount of pigment expressed over time, causing a dark or black color to become prominent on the fins and body.


Illness can result in various color changes for your betta. If you notice any of the following conditions, begin treatment as soon as possible.

Fin Rot

Color change of red or black, located only on the fins and accompanied by fraying, may indicate fin rot.

This bacterial or fungal infection can affect fish with already weakened immune systems.

What to Do: For mild fin rot, simply correcting the water conditions and letting the fins heal is sufficient.

For moderate or severe cases, quarantine your fish and treat them with aquarium salt or medicine in the water.

While most fins will grow back looking the same, some newly regrown fins can have a different pigment, causing them to appear darker or lighter in color.

Bacterial Infection

If you notice fluffy white patches on your fish, one cause could be the bacterial infection columnaris. With this infection, your fish can turn white and develop skin lesions.

What to Do: Have your fish seen by a veterinarian and follow the medication treatment plan completely before returning your fish to the community tank.

Parasitic Infection

Anchor Worms

Anchor worms are parasites not often seen in home aquariums. These parasites are easily visible and look like white, red, or green strings attached to your fish.

If you notice these along with behavior changes, such as rubbing against decorations in the tank, then your fish may have a parasite. They may also be lethargic and breathe heavily.

What to Do: The treatment for anchor worms lasts 28 days to account for the parasite’s life cycle.

Treatment options include over-the-counter parasite medication powders or a combination of physical removal of the parasites, followed by treatment with potassium permanganate and aquarium salt.


Ich is common in home aquariums. When infected, your fish will be speckled with white spots over their fins and body.

As with anchor worms, your fish will not have much energy and may attempt to relieve the annoyance of these parasitic protozoans by rubbing on items in the tank.

What to Do: Take your fish to a veterinarian for diagnosis. Treatment takes around 12 days and involves a “whole tank” approach using medication in the water and controlling the water temperature to speed up the parasite’s life cycle.

Always follow the medication instructions, including whether water changes are required between doses.


Infection with the Oödinium parasite results in a golden or rust-colored, dusty coating on your fish’s scales.

As with other parasitic infections, your fish will not move around much, and they may have trouble breathing.

Watch for your fish holding its fins near its body, skin ulcers, and cloudy eyes.

What to Do: Treatment involves reducing the amount of light to the tank, as this parasite can also photosynthesize.

Raise the tank temperature to between 82 and 85°F (27 to 29°C) and slowly add a teaspoon of aquarium salt for every gallon of water.

Keep your fish isolated for up to four weeks to ensure the parasites go through their life cycle completely.

Fungal Infection

Fungal infection can result in your fish appearing pale with noticeable fuzzy white patches. They may have trouble breathing and may not move around as usual.

What to Do: Treat them for at least three days in a quarantine tank using anti-fungal medication or aquarium salt (1 Tbs per 5 gallons of water).

Swim Bladder Disease

Swim bladder disease can result in numerous symptoms, one of which can be a paling of your fish’s color due to stress.

Look also for behavioral changes in your fish, such as loss of appetite, laying on its side, floating near the water’s surface, or staying near the tank bottom.

They are unable to properly orient themselves and may swim sideways or even upside down.

What to Do: This illness can have different causes, so first, determine what might have exacerbated it.

Common causes are gastrointestinal issues due to poor diet, low water temperatures or rapid fluctuations, or bacterial/parasitic infections. Once you know the cause, treat your fish accordingly.

How to Keep Your Betta’s Color Bright

Provide the Best Environment

Proper tank size, steady water parameters, and adequate hiding spaces make for the ideal, stress-free environment for your betta.

Plan on a minimum of five gallons for your tank, install a heater and thermometer, clean your tank and perform partial water changes, and test your water regularly.

Make sure any tank mates are compatible, not only in water parameters but also in temperaments. Be careful to not overstock your tank.

Feed Them Well

Start off with a high-quality betta pellet and feed them only two to three pellets per day.

In addition, supplement their diet with nutrient-rich foods, such as daphnia, to keep their colors vivid.

Treat Illness Promptly

The faster you provide treatment for your sick fish, or the faster you correct any water or tank conditions that are causing your betta to change color, the better the prognosis for your fish.

Closing Thoughts

Most of the reasons your betta fish may be changing color are preventable. Checking in on your betta fish daily will help you stay aware of any color changes.

Maintain proper water conditions, a calm community tank environment, and varied diet for your betta.

If you notice a color change that cannot be attributed to life cycle changes or genetics, treat your fish promptly for the best chance of recovery.

Let’s hear from you! What successes have you had when your betta fish changed color?