Single Fish Death
Remove dead fish immediately. Test water — ammonia may already be rising.
50% water change. Dose Prime to detoxify any remaining ammonia.
Multiple Deaths in 24-48 Hours
Bigger problem. Likely cause: ammonia/nitrite spike, disease, water quality crash.
Test water IMMEDIATELY. Determine cause before adding more fish.
Tank Recovery Protocol
Step 1: 50% water change. Verify ammonia drops.
Step 2: bottled bacteria (Dr. Tim or similar) to boost colony.
Step 3: feed remaining fish lightly for 7 days. Less waste = faster recovery.
Step 4: monitor daily for 2 weeks before considering tank recovered.
When to Empty and Restart
After massive die-off (10+ fish): consider full reset.
Bleach disinfect: 1:10 bleach for 24 hours, rinse extensively, restart cycling.
Salvage what you can: décor, plants (rinsed), substrate (if cleaned thoroughly).