1. Skipping the Cycle
Results in mass die-off. Always cycle tank first for 4 to 6 weeks.
2. Overfeeding
Causes ammonia spikes and cloudy water. Follow 2-minute rule.
3. Overstocking
Too many fish exceed biological filter capacity. Stock gradually.
4. Impulse Buying
Buying fish without researching requirements leads to mismatches and mortality.
5. Wrong Tank Size
Small tanks are harder. 20 gallons is a safer starting point than 5.
6. Skipping Water Changes
Nitrate accumulation stresses fish even when cycle is complete.
7. Never Testing Water
Fly blind and you miss ammonia spikes until fish die.
8. Mixing Incompatible Species
Aggressive + peaceful = daily casualties.
9. Not Quarantining New Fish
One sick fish can infect every resident of your display.
10. Abandoning the Hobby After First Loss
Every keeper loses fish. Learn from it and continue.