- Oxygen Deprivation: Check if the water is adequately aerated. Insufficient oxygen can cause goldfish to become lethargic and sink to the bottom.
- Water Quality Issues: Test the water parameters for ammonia, nitrites, and pH. High levels of harmful substances can stress or sicken goldfish, causing them to stay at the bottom.
- Swim Bladder Disorder: A condition where goldfish have difficulty maintaining their buoyancy. It can be caused by various factors, including constipation, overfeeding, or physical injury.
- Disease or Infection: Check for signs of illness, such as clamped fins, discoloration, or skin lesions. Certain diseases can cause goldfish to become inactive and stay on the bottom.
- Environmental Stress: Sudden changes in water temperature, pH, or the addition of new tank mates can stress goldfish, leading to lethargy and bottom-dwelling behavior.
Action to take:
1. Water Check: Test the water quality immediately and make any necessary adjustments to ensure optimal conditions.
2. Aeration: Increase water oxygenation using an air pump or bubbler.
3. Feed Adjustment: If overfeeding is suspected, reduce the food amount or frequency and ensure a varied, balanced diet.
4. Treatment: If signs of disease are observed, consult with a veterinarian or experienced aquarist for proper diagnosis and treatment.
5. Minimize Stress: Avoid sudden changes to the tank environment and provide stable, suitable living conditions.
If your goldfish remains at the bottom despite addressing these potential causes, it's advisable to seek professional advice or consult with a veterinarian specializing in aquatic pets for further guidance.