Guppy fish are famous for their attractive and bright colors, especially when it comes to male guppies. But, guppies can lose their color and turn grey for various reasons and finding the particular reason behind it is essential. So, Why is my guppy fish turning grey? Let us find out.
Ammonia spike and diseases like fin rot are the primary reasons your guppy fish turn grey. Other reasons include stress, overcrowded tank, age, and low-grade food. Feed your guppies high-quality nutritional food and ensure good water conditions to prevent your guppies from such issues.
This article will discuss why guppy fish turn grey and know how to treat and prevent guppy fish from such issues. So, let us get into it.

Contents
My guppy Is losing Its natural color.
There can be numerous reasons behind guppy fish losing their natural color, of which poor water conditions and disease are the primary reason.
Other reasons include stress, inadequate water parameters, overcrowded tank, and lack of light in your guppies aquarium.
Guppy getting older will also start losing its natural color.
So, age is also the factor behind guppy fish losing their color.
Also read: Why Do Guppies Lose Their Color?
Is It normal for guppies to turn grey?
It is not normal for guppy fish to turn grey.
However, it is normal if old age is the factor behind guppy fish losing color and turning grey.
But guppy fish turning grey because of some other reason is a matter of concern and requires necessary treatment.
Otherwise, guppy fish losing color and turning grey is a clear sign of suffering.
Let us discuss all the possible reasons behind guppy fish turning grey.
Also read: Why Is My Guppy Fish Turning Black?
What are the reasons behind my guppy fish turning grey?
These are the reasons behind your guppy fish turning grey:
- There has been an ammonia spike in your guppies aquarium.
- Your guppies aquarium water quality is poor.
- Your guppy’s aquarium water parameters are not stable and adequate.
- Your guppy is suffering from a disease.
- Your guppy fish is under stress.
- Your guppy fish is not getting enough light.
- Your guppy fish is aged.
- Your guppy fish is not getting high-quality nutritional food.
Ammonia spike
Ammonia spike in your guppy fish aquarium can make your guppy fish turn grey.
Usually, ammonia develops in a new tank but can also appear in a well-established tank with poor water quality.
Ammonia spike results in burning your guppy fish skin and gills, appearing grey skin because of the burns.
Your guppy fish can suffer from a life-threatening condition because of an ammonia spike.
Poor water quality
Bad water conditions can also be the root cause behind your guppy fish losing color and turning grey.

Guppy fish living in poor water conditions will come under stress and lose their appetite.
Poor water conditions will make them prone to various diseases and parasites, resulting in losing color and turning white, black, and grey.
Also read: Can Guppy Survive In Muddy Water?
Inadequate water parameters
Inadequate water parameters can also make your guppy fish turn grey.
Inadequate pH level results in a spike of ammonia, burning your guppy fish skin.
Inadequate and unstable water temperature can make your guppy fish come under stress and prone to diseases.
Guppy fish suffering from a disease
Guppy fish suffering from diseases like fin rot can lose their color and turn grey.
Fin rot is common in guppies and is caused because of poor water conditions and stress.
Fin rot is a disease that is very easy to prevent but challenging to cure.
Usually, fin rot is caused by pseudomonas, vibrio, and Aeromonas bacteria. However, stress and poor water conditions remain the primary factor.
Stress
Stress can also make your guppy fish lose their color and turn grey.
Guppy fish become lethargic and lose their appetite when under stress for a long time.

Also, you must know that stress can make your guppy fish prone to various diseases and parasites.
These are the reasons behind your guppy fish can come under stress:
- Poor water conditions
- Inadequate and unstable water parameters
- Aggressive tankmates
- Overcrowded tank
- Physical injury
- Irregular supply of food
- Inadequate male to female ratio of guppies
- Lack of hiding spots
- Female guppy being pregnant
- Guppy suffering from diseases
Also read: Are My Guppies Stressed?
Lack of light
An aquarium in a place with no direct or indirect sunlight source can make your guppy fish lose their color.

Consider adding an aquarium light to your guppies aquarium and keeping it on for at least 3 hours a day.
Your guppy fish is aged.
Your guppy fish may be losing its color and turning white as it gets old.
Age can also be the factor behind your guppy fish losing its natural color and turning white.
Guppy is not getting high-quality nutritional food.
Not feeding your guppy fish good quality food can make them lose their color and turn white.
Guppy fish require various nutritious food to enhance their color.
Irregularly feeding them low-grade food will make your guppy fish weak and lose its natural color.
Also read: Why Is My Guppy Not Eating?
How to treat guppy fish turning grey?
If there is an ammonia spike in your guppies tank, and it is why your guppy fish loses its color and turns grey, a major water change is required.
Check the ammonia level using the API Ammonia test kit as it shows the exact result.
You can buy it from Amazon API TEST KIT.
Perform a 35% water change every day or alternate day until the ammonia level reaches 0ppm.

A high ammonia spike can also require 80% water change to lower the ammonia level.
Ammonia spike can make your guppy fish suffer from a critical condition, and even they can pass away.
If fin rot is the reason behind your guppy fish losing its natural color, it is necessary to isolate the guppy fish and treat them with antibiotics.
However, before treating fin rot, it is essential to know if the reason behind fin rot is fungal or bacterial.
Also, how severe is the condition as the treatment will be processed according to that.
You can read my article to know all about treating fin rot, its symptoms, the severity of fin rot, and whether it is bacterial or fungal.
Also read: How To Treat Guppy Fin Rot?
How to prevent our guppies from such Issues?
Ensure these things to prevent your guppy fish from such issues:
- Provide your guppy fish with good water conditions.
- Ensure adequate and stable water parameters.
- Feed your guppy fish high-quality nutritional food.
- Avoid overcrowding your guppy fish tank.
- Provide a stress-free environment for your guppy fish.
Good water quality
Providing your guppy fish with good water quality will prevent them from such issues and other diseases and parasites.
Perform a weekly water change of 35% to ensure good water quality.
Whenever you perform a water change, use a gravel siphon to siphon all the sold debris and other waste.
| Particulars | Guppy Requirement |
|---|---|
| Nitrate | Below 25ppm |
| Nitrite | 0ppm |
| Ammonia | 0ppm |
Consider adding a good filtration system with biofilter media to keep the water clean and safe from harmful chemicals like ammonia and nitrite.

We advise you to purchase a Fluval High Performance Aquarium filter to maintain your tank’s water quality.
You can buy it from Amazon Fluval High Performance Aquarium Filter.
Also, you should add live aquatic plants to your guppies tank to keep the water clean and ensure enough oxygen for your guppies.
Also read: How Often To Change Guppy Water?
Adequate and stable water parameters.
Providing your guppy fish with adequate and stable water parameters will help you prevent such issues in your guppy fish.
| Particulars | Guppy Requirement |
|---|---|
| Water temperature | 72-82 °F. |
| Water pH level | 6.7-7.8 |
| Water TDS level | 400-600ppm |
Provide your guppy fish with a water temperature between 72-82 °F.
Ensure to maintain the water pH level between 6.7 and 7.8.
The best TDS level for guppy is between 400-600ppm.
You must know that with adequate water parameters, stable water parameters are equally essential to prevent your guppy fish from such issues.
So, consider adding a heater to your guppy fish tank to keep the water temperature stable.
Also read: Do Guppy Need Heater? (Heater Watt Size Guide)
Feed high-quality nutritional food to your guppies.
Food plays a major role in enhancing your guppy fish’s attractive color.
Feeding low-grade food to your guppies will affect their color, making them lose their color.
| Guppy Food | Serving Quantity | No of Times |
|---|---|---|
| Mosquito larvae | 10-15 pieces | 2-3 times a week |
| Brine shrimp | One small pinch at a time | 1-2 times a week |
| Veggie pellets | One small pinch at a time | 2-3 times a day |
| Bloodworms | One small pinch at a time | 1-2 times a week |
| Tubifex Worms | One small pinch at a time | 1 time a week |
| Boiled peas | Half a pea per guppy | 2-3 times a week |
| Blanched zucchini | One small slice | 2-3 times a week |
