Color fading in betta fish is a common phenomenon, which can be caused by natural physiological changes, environmental stress, or health issues. The specific causes and corresponding solutions are as follows:
I. Normal Color Fading Scenarios
1. Breed Characteristics
Marble-patterned bettas undergo periodic color changes due to genetic factors—this is a normal occurrence.
Juvenile bettas (under 2 months old) will gradually develop their adult coloration after shedding their blue-green protective color.
2. Age-Related Factors
Elderly bettas (over 18 months old) naturally fade in color as their pigment metabolism declines, similar to how humans develop gray hair.
3. Breeding Period Changes
Male bettas display brighter "breeding colors" to attract mates, while female bettas may also experience temporary color shifts.
II. Abnormal Color Fading: Causes and Treatments
1. Environmental Stress
Sudden Water Quality Changes: If the pH level falls outside the 6.0-7.5 range or the water temperature fluctuates by more than 2℃, bettas may fade due to stress. Maintain a water temperature of 25-28℃ (77-82.4°F) and slightly acidic soft water.
Excessive Light: Direct strong light can easily cause bettas’ color to turn pale. It is recommended to use dark-colored substrate and limit light exposure to 4-6 hours per day.
Inadequate Space: Cramped environments increase stress. Use a tank of at least 20cm in length and add hiding spots (e.g., plants, caves).
2. Health Issues
Disease Infections: Conditions like ich (white spot disease) or saprolegniasis (water mold) are accompanied by white spots or cotton-like growths on the body. Isolate the infected fish and treat it with methylene blue or a salt bath.
Malnutrition: A lack of astaxanthin or carotenoids can lead to color fading. Feed frozen bloodworms or color-enhancing food twice a week.
3. Stress from Transportation or Tank Changes
Bettas may experience temporary color fading during the 3-7 day adaptation period to a new environment. They will recover after being left in a quiet space to acclimate.
III. Recovery and Preventive Measures
Water Quality Management: Replace 1/3 of the tank water weekly, and add almond leaves to adjust the pH level to 6.5-7.0.
Nutritional Supplementation: Alternate between color-enhancing food (containing spirulina or astaxanthin) and live food (e.g., brine shrimp) for feeding.
Stress Reduction: Avoid frequent tank changes; use a mirror to briefly stimulate the betta’s territorial instinct (no more than 5 minutes per day)—this helps maintain vibrant coloration.
IV. Precautions
Color changes in marble-patterned bettas are a genetic trait and require no intervention.
If color fading is accompanied by fin damage or rapid breathing, check the fish for underlying diseases promptly.