My Betta Fish Has Black Gills (Symptoms & Preventions!)

My Betta Fish Has Black Gills

Many people nourish betta fish in their aquarium as a hobby to decorate and enhance the beauty of their house. 

You may be thinking, is it a disease or the natural color of the gills of my betta if my betta fish has black gills? If it is a disease then it can be possible to minimize it through quick identification and treatment.

If you want to learn more, you’ve come to the correct place. Let’s discuss the matter and get to know more.

My Betta Fish Has Black Gills

If my betta fish has black gills, it is a disease. This disease is caused by dirty water, unfiltered water, uncycled tank, low temperature, and severe ammonia develop this disease, makes the fish feel lethargic. Immediate treatment can remove the black spot from the gills of my betta fish.

Black gills can be the natural color of your betta fish and jet black gills can cause the death of your betta fish.

Some Simple Steps to Remove the Black Gills

What you’ll need-

  • The source of stress
  • Water change
  • Gravel vacuum
  • Antibiotics
  • Rock salt
  • Temperature
  • Hospital tank
  • Food
  • Repetition
  • Some water
My Betta Fish Has Black Gills

Black gill removal procedure-

Step 1: Locate the source of stress

Stress leads a fish to get sick, maybe your water is too cold or too unhygienic or the current is too fast which causes stress.

Step 2: Change the water

You need to change 30% of the entire tank water to remove the dirt from the water and clean it. 

Step 3: Select a gravel vacuum

You need to choose a gravel vacuum to get the water changed. Use the vacuum on the bottom of the tank to maintain a stress-free environment.

Step 4: Use the antibiotics 

Select antibiotics named erythromycin and follow the instructions as a treatment to improve the condition of your fish.

Step 5: Put some rock salt

If the antibiotics are not working out then put some aquarium salt or rock salt instead of antibiotics. 

Rock salt works well for bacterial infections as black gill is a bacterial infection.

Step 6: Set the temperature

After putting rock salt you need to set the heater temperature from 30-32° to continue the treatment.

Step 7: Arrange a hospital tank

After putting in rock salt you may need to arrange a hospital tank as rock salt is harmful to aquarium plants and snails and treat the sick fish separately.

Step 8: Feed some food

You need to provide food to your betta fish after 12 hours of starting the treatment otherwise, the fish may not be able to fight against bacteria.

As treatment begins, the sick fish will improve and be able to eat the food, or else it may get sick again.

Step 9: Repeat the treatment

It is a 10 days long treatment, you need to continue the treatment every 3 days and need to do it 3 times. From the second time, you can see the improvement of your fish.

This treatment can ensure your fish remove the black spot from black gills without any medicine.

Step 10: Put the water again

You need to put the same amount of water in the tank that you have removed after each treatment.

It’s better to remove the 20% water from the tank after the end of the treatment to balance the salt level.

If you’re still unclear about the process, you can view the videoes to have a better understanding.

What Type of Fish Suffers From Black Gills?

Black gill is a bacterial infection of betta fish. 80% of this disease can be seen in parrot fish and 20% in other fish which can be removed through treatment.

How Does the Sick Betta Fish Behave and Appear?

Sick betta fish can be easily identified by their behavior and appearance. When a fish gets sick it becomes lazy, inactive, less aggressive, can’t eat food, and hides in different caves, logs, and plants.

Black gills can affect the fins, caudal, pectoral, anal, and dorsal of a betta fish.

How Can You Identify Whether the Black Gill Is Natural or a Disease?

Sometimes black gills are natural for betta fish as fish explores normally and seems healthy.

When the fish is lazy and unable to eat, you can determine it as sick.

To identify the sick betta fish you need to use a test kit for the chemicals including ammonia, nitrates, and nitrites. 

Keep checking your aquarium water every day to maintain all the chemicals level frequently to keep the water clean.

What Are the Reasons for Black Gills Disease?

Bacterial infections can cause black gill disease in your betta.  The main reasons for black gills are-

  • Dirty Water
  • Low temperature
  • Imbalance of the chemical substances

Reason 1: Keeping dirty water

The main reason for black gill disease is keeping the water dirty. You need to change the water once in a week to maintain hygiene.

Reason 2: Maintaining low temperature

If the temperature of your aquarium is low, 25° or below, then there is a chance to be affected by this disease. 

You need to set the temperature from 30-32°.

Reason 3: Imbalance of the chemical substances

If the ammonia level, nitrate level, and nitrite level rise, it creates the water condition bad and develops the black gill disease in betta fish.

As you are well aware of the reasons for black gills, watch the video below to know how to save your sick betta fish.

What Are the Levels of Ammonia, Nitrate, and Nitrite That Should Be Maintained?

If you want to set up your aquarium as a cycled tank for months, then you need to maintain 0 ammonia, 0 nitrites, and under 20 nitrates.

What Is Ammonia Poisoning in Fish?

When the ammonia range is too high in a tank and it starts to harm the fish as a poison. 

Ammonia poisoning develops black gills in a fish and makes the fish more lethargic.

What Types of Black Gills Cause Death?

Jet black gills lead a fish to death and old fishes are more vulnerable to black gills.

How to Prevent Black Gills in Betta Fish?

If you follow some tips from the very beginning, then your fish become proactive and they won’t get sick.

  • Add nitrifying bacteria to balance the water and chemicals in your tank.
  • Change your tank water frequently to remove the dark.
  • Filter the water to remove the harmful substances
  • Set up the temperature
  • Create the perfect environment in the tank for your betta fish.
How to Prevent Black Gills in Betta Fish?


If you’re wondering about the condition, my betta fish has black gills, symptoms, and preventions! Then in this article, I’ve suggested some tips which will help you to recover from it.


  • It is a disease 
  • Dirty water
  • Unfiltered water
  •  Uncycled tank
  • Low temperature
  • Severe ammonia 
  • Makes the fish feel lethargic

Besides that, now you know some tips, how it can be removed, and the reasons why it happens.

Frequently Asked Questions

1. What’s the Life Expectancy of a Betta Fish?

The lifespan of a betta fish is 2-4 years. If you keep the tank clean and maintain a diet chart then your fish will live longer.

Select other fish from the tank wisely and create a stress-free environment to make a betta fish’s health sound.

2. Can Betta Fish Survive Ammonia?

Ammonia burns the gills of the betta fish. Despite ammonia being harmful to the betta fish, betta can tolerate ammonia more than any other fish. 

To prevent betta fish from ammonia, don’t overfeed the fish as it produces ammonia, the harmful gas.

3. How Often Should I Feed My Foo Fish?

You need to follow a healthy diet chart for your betta fish. You should provide high proteins and select a betta pellet to ensure the perfect level of nutrients for a betta fish.

You should give the betta two to four pellets a day and provide frozen foods weekly.

4. Can You Add Tap Water to the Fish Tank?

Tape water is safe for the tank but it contains chlorine which kills fish and sometimes tape water contains high ammonia which is harmful to betta fish.

You May Also Like: