Cause 1: Constipation
Most common in fancy goldfish and bettas. Eating dry pellets that swell in stomach causes pressure on swim bladder.
Treatment: 3-day fast. Then feed thawed peas (skin removed) for 3 days. Most cases resolve.
Cause 2: Bacterial Infection
Persistent floating issues that do not resolve with fasting. Often accompanied by clamped fins or lethargy.
Treat with Kanaplex or Furan-2 antibiotics. May need 7-14 day treatment course.
- ✦Soak dry food briefly before feeding — reduces gas in gut
- ✦Switch to sinking pellets for fancy goldfish
- ✦Lower water level for severely affected fish — easier to surface for air
Cause 3: Birth Defect (Permanent)
Some fancy goldfish (especially Ranchu, Lionhead) have permanent swim bladder issues from selective breeding.
No cure — manage with shallow water (8-10 inches), sinking food, and patience. Fish can live full lives with care.
When to Euthanize
Fish unable to reach food for 5+ days, severe distress, secondary infections from constant rubbing on substrate.
Clove oil sedation followed by ice bath is the humane standard. Never flush a sick fish.