Gas Bubble Disease

Symptoms

Spotting illness early gives the best chance of a cure, so check your fish daily at feeding time. Tiny gas bubbles trapped under the skin, in the fins, or behind the eyes, sometimes causing buoyancy problems. If you see several of these signs together, act promptly rather than waiting.

Causes

Caused by water that is supersaturated with gas - often from a leak on the intake side of a pump, or cold water warming rapidly, or heavy aeration under pressure. In nearly every case the underlying trigger is stress, poor water quality, or the introduction of an infected fish - all of which weaken a fish's natural defences.

Treatment

Find and fix the source of excess gas (check for pump intake leaks), increase surface agitation to let excess gas escape, and the bubbles usually resolve once the water is no longer supersaturated.

While treating, increase aeration, remove activated carbon from the filter (it absorbs medication), finish the full course even after the fish looks better, and keep the water immaculate with regular changes. Always dose for the tank's true water volume and follow the product instructions.

Prevention

Check pumps and plumbing for air leaks, age and aerate new water, and avoid rapidly warming very cold water. The golden rules are simple: quarantine every new fish for 2-4 weeks, never overstock or overfeed, avoid sudden temperature or chemistry swings, and do regular partial water changes. A stable, clean, low-stress aquarium prevents the large majority of disease.

FAQ

This information is general guidance, not veterinary advice. Consult an aquatic vet for serious cases.