Ammonia Poisoning
Chemical burns caused by ammonia in the water. Damages gills and causes red or bloody streaks on the body and fins. Common in new tanks, after overfeeding, or when beneficial bacteria die off.
Check these symptoms in your tankSymptoms of Ammonia Poisoning
- Gasping at surface
- Red streaks or inflammation
- Rapid gill movement / labored breathing
- Lethargic / hiding more than usual
- Refusing to eat
- Excess mucus / slime coat
How to treat Ammonia Poisoning
- Perform a 50% water change immediately with dechlorinated water
- Add Seachem Prime or a similar ammonia detoxifier
- Test the water: ammonia should read 0 ppm
- Reduce feeding until ammonia is under control
- Add beneficial bacteria (Seachem Stability, API Quick Start)
- Increase aeration to help fish breathe
How to prevent it
- Cycle the tank fully before adding fish
- Do not overstock or overfeed
- Perform regular water changes and test parameters weekly
- Rinse filter media in tank water, not tap water
Conditions with similar symptoms
Highly contagious bacterial disease. Appears as white/gray patches, often starting at the dorsal area or mouth. Sometimes called "cotton mouth" or "saddleback". Progresses rapidly, fish can die within days.
Includes skin and gill flukes, anchor worms, and fish lice (Argulus). Fish may scratch against objects (flashing) and produce excess mucus. Often introduced with new fish or live food.
The most common aquarium disease. Caused by the parasite Ichthyophthirius multifiliis. Looks like salt grains on the fish's body and fins.
Not sure? Use the symptom checker
Many fish diseases look alike. Pick the symptoms you see in the free fish disease checker to compare likely causes, or scan a test strip to rule out a water problem first.