Why Is My Guppy Fish Turning Black? (Reasons+Treatment+Prevention)

Guppy fish are hardy fish and the best option for beginners. However, they are sensitive to infections and parasites, which makes us worry when they suffer from issues like turning black.

It is essential to know the exact reason behind your guppy fish turning black, as there can be numerous reasons behind such issues. So, Why is my guppy fish turning black? Let us find out.

Ammonia poisoning is the primary cause of guppy fish turning black. Other reasons include genetics, stress, and black spot disease. Ensure maintaining the ammonia level at 0ppm, avoid overfeeding, and provide a stress-free environment to your guppy fish to prevent them from turning black.

This article will discuss why guppy fish turn black and how to treat and prevent guppy fish from turning black. So, let us get into it.

My guppy fish Is turning black.

There can be various reasons behind your guppy fish turning black, of which the primary reason is an ammonia spike.

Other reasons are genetics, black spot disease, and stress.

You cannot do anything if genetics is the reason behind your guppy fish turning black.

If there are other reasons behind guppy fish turning black, immediate action is required.

Issues like black spot disease and an ammonia spike can make your guppy fish suffer from a critical condition, and even they can pass away.

Why Is my guppy getting a black spot?

Your guppy can develop a black spot because of genetics.

If your guppy has a black tail growing, it may be because of genetics.

However, if genetics is not the reason, infection and parasites are the easy explanation behind such coloration.

Ammonia poisoning in your guppies tank will result in guppies developing black spots because of getting burned.

Black spot disease can also be why your guppy fish get black spots all over their body.

All these issues require immediate action to recover and prevent your guppies from such problems.

What are the reasons behind guppy fish turning black?

These are the reasons behind your guppy fish turning black:

  1. There is a high amount of ammonia present in your guppies tank.
  2. Your guppy fish is suffering from a black spot disease.
  3. Your guppy fish is suffering from infection and parasites.
  4. Your guppy fish is under high-level stress.
  5. It is because of genetics.

Ammonia spike

Ammonia spike is the primary reason behind your guppy fish turning black.

A high ammonia level burns your guppy fish body, turning it black. 

Usually, ammonia develops in a new tank but can also develop in an established tank if there is poor water quality.

Fish leftover and dead and decaying plants and fish causes ammonia spikes in the aquarium.

A poor filtration system also results in ammonia spikes.

An overcrowded tank with guppies and other fish will also have a risk of an ammonia spike. 

Black spot disease

Black spot disease, also known as fluke disease, is a freshwater fish disease caused by the flatworms larvae.

Guppy suffering from black spot disease will develop tiny black spots in their fins, gills, and all over the body. 

This disease’s life cycle starts from a bird to snail to fish. 

The parasite that causes black spot disease grows to the level of sexual maturity in the infected bird’s intestine. 

The worms pass the eggs with the droppings of the bird. 

The eggs get hatched when they reach the water, becoming free-swimming organisms. 

Now, these organisms penetrate snails present in the water for further development. 

Now, after leaving the snails, they set into the skin of the fish, forming a cyst. 

When the birds eat the infected fish, the cycle gets repeated.

Infection and parasites

Infection and parasites can also be why your guppy fish turn black. 

If your guppy fish develops a black fin, it may suffer from an infection.

However, confirm that the reason behind such an issue is infection or genetics.

Genetics can also be the reason behind the guppy tail turning black.

High-level stress

Stress due to environmental factors can also be why guppy fish turn black. 

These are the reasons which can make your guppy fish come under stress:

  1. Inadequate and unstable water parameters.
  2. Poor water quality.
  3. Irregular food supply.
  4. Overcrowded tank.
  5. Inappropriate male and female ratio of guppies
  6. Presence of aggressive fish in your guppies aquarium
  7. Lack of hiding spots.
  8. Illness
  9. Injury
  10. Oxygen deficiency in your guppy’s tank

Also read: Are My Guppies Stressed?

Genetics

Genetics can also be the reason behind your guppy fish turning black.

Guppy fish turning black because of genetics will remain black and live like that for the rest of their lives.

Guppy will not suffer from anything if the reason behind turning black is genetics. 

So, there is nothing to worry about if genetics is why guppy fish turn black. 

How to treat guppy fish with such an Issue?

Ensure these things to treat your guppy fish that has turned black:

  1. Perform a major water change (If the reason behind is an ammonia spike)
  2. Consult a marine vet (If the reason behind is infection and parasites)

Perform a major water change

Performing a major water change of 80% is necessary when there has been an ammonia spike in your guppy’s aquarium.

Dead plants and fish are the primary reasons behind ammonia spike.

Contaminated water also results in an ammonia spike in your guppy’s aquarium.

So, detect the ammonia spike in your guppy’s aquarium and eliminate the reason.

Make sure to treat the water using a water conditioner to dechlorinate the water.

We recommend using the API water conditioner as it will help you eliminate chlorine, chloramine, ammonia, nitrite, nitrate, and heavy metals from the water.

You can buy this product on amazon: API TAP WATER CONDITIONER.

Consult a marine vet

If you are a beginner and know nothing about the guppies, consider consulting a marine vet in such situations.

Guppy fish turning black can be the reason behind infections and parasites.

Proper medication is needed for infection and parasites.

So, consider consulting a marine vet to treat your guppy fish. 

How to prevent our guppy fish from turning black?

Follow these things to prevent your guppy fish from turning black:

  1. Maintain ammonia level and keep your guppy fish aquarium clean.
  2. Provide adequate and stable water parameters to your guppies.
  3. Provide a stress-free environment for your guppy fish.
  4. Avoid overfeeding your guppy fish.
  5. Isolate new fish in a separate tank before adding them to your guppy’s aquarium.

Maintain ammonia level and keep the tank clean

The ammonia spike in your guppies tank is the primary reason your guppy fish turns black.

It is necessary to check the ammonia level regularly to ensure that it is not high. 

We recommend using the API Ammonia test kit as it tells you the exact result. 

You can purchase it from Amazon API TEST KIT.

Ammonia develops in an aquarium with leftovers, dead fish and plants, and poor water conditions.

Performing a weekly water change of 30% will eliminate such issues and keep your guppy fish aquarium clean.

Consider adding a good filtration system with biofilter media to keep your guppy’s aquarium clean from leftovers, solid debris, and harmful chemicals like nitrite and ammonia. 

Also, you can add live aquatic plants to your guppy’s aquarium, as it will help you keep the water clean and ensure enough oxygen in the water for your guppies to live comfortably. 

Adequate and stable water parameters

Providing your guppy fish with adequate and stable water parameters will prevent your guppies from turning black. 

Guppy fish are tropical fish and live in warm water.

Ensure providing your guppy fish water temperature between 72-82 °F.

Guppy fish live in a water pH level between 6.7 and 7.8.

The best TDS level of guppy fish is between 400ppm to 600ppm.

With adequate water parameters, you must know that stability in water parameters is equally necessary to prevent your guppy fish from stress and such issues.

So, you can consider adding a heater to your guppy fish aquarium to ensure a stable water temperature. 

We recommend using the Fluval M200 Submersible heater for your tank.

You can buy this product at amazon: Fluval M200 Submersible Heater.

Also, a digital thermometer will help you check the water temperature.

We recommend using the Aquaneat Aquarium Thermometer as it shows the accurate temperature.

You can buy this product from amazon: Aquaneat Aquarium Thermometer.

Also read: What Is The Ideal Water Temperature For Guppies?

Provide stress-free environment 

Providing a stress-free environment to your guppy fish will prevent such issues.

Ensure these things to provide your guppy fish stress-free environment:

  1. Provide good water quality to your guppy fish by performing a weekly water change.
  2. Ensure adequate and stable water parameters.
  3. Add lots of live aquatic plants.
  4. Avoid overcrowding your guppy fish tank by keeping one inch of fish per one gallon of water. 
  5. Regularly feed your guppy fish.
  6. Avoid adding aggressive fish to your guppy fish tank.
  7. Provide a large enough space for your guppies to live and swim comfortably.
  8. Add an air pump to ensure enough oxygen in the water for your guppy fish to breathe.
  9. Add a heater to your guppies tank to ensure a stable water temperature.

Following all these will keep your guppy fish away from stress, and they will live comfortably. 

Also read: What To Do If My Guppy Is Stressed?

Avoid overfeeding your guppy.

Overfeeding your guppy fish will result in more waste in your guppy’s water. 

Overfeeding can also cause constipation and bloating to your guppy fish. 

Provide your guppy fish food in a quantity that they can finish eating in one to two minutes.

If your guppy fish is taking more than one to two minutes to finish the food, you are overfeeding them. 

If they take seconds to finish eating, you are underfeeding them.

Also read: Can Guppy Die From Overfeeding?

Isolate the new fish 

When we buy a new fish from a pet store or a breeder, isolating them for 3-4 weeks is necessary to see if they are suffering from any issues.

Infected and sick fish can infect your home aquarium, resulting in your guppies getting sick. 

So, isolate the new fish for weeks to see if they are healthy or suffering from any issues.

Once you confirm that the fish is healthy, you can introduce them to your home aquarium. 

Conclusion:

There can be numerous reasons behind your guppy fish turning black, of which ammonia poisoning is the primary reason.

Other reasons are stress, infection, and genetics.

If genetics is the reason behind your guppy fish turning black, you have nothing to do, and your guppy will live like that for the rest of its life.

Other reasons require immediate action.

Consult a marine vet when your guppy fish shows additional symptoms like being lethargic and losing appetite, as infection and parasites can be the reason behind your guppy fish turning black.

Ensure maintaining the ammonia level at 0 ppm and keep the water clean to prevent your guppy fish from such issues.


Reference: Science, NCBI, ResearchGate

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