Neon Tetra Disease

Symptoms

Spotting illness early gives the best chance of a cure, so check your fish daily at feeding time. Fading colour, a pale or 'broken' stripe, a lumpy or curved spine, difficulty swimming and wasting. Despite the name it affects many small fish, not just neons. If you see several of these signs together, act promptly rather than waiting.

Causes

An incurable microsporidian parasite spread by eating infected material, including dead fish, in the tank. 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

There is no reliable cure. Remove and humanely euthanise affected fish promptly to stop the spread, and remove any bodies immediately. Maintain excellent conditions for the rest.

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

Quarantine new fish, remove dead fish at once, and avoid buying from tanks with sick or deformed individuals. 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.