Goldfish Swimming Head-Down: Swim Bladder Disorder

10-inch white goldfish has bulging sides near tail, swims head-down. Green mossy growth on pond edges after adding overwintering plants.

Diagnosis: Swim Bladder Issue

Classic sign of swim bladder dysfunction. Common causes: constipation, infection, or physical injury.

Treatment

1. Stop regular food.
2. Feed cooked, peeled peas (fiber clears digestive tract).
3. In cold water, fish eat slowly; allow time.

The "moss" is likely benign algae or biofilm from plant decay. Remove excess debris but plants generally help water quality. Salt (0.05%) can support recovery.