1
Q
nitrogen cycle
A
ammonia (NH3) → nitrite (NO2) → nitrate (NO3)
2
Q
what causes ammonia
A
- decomposition of fish waste
- decaying food
- dead fish
- fish continually excrete ammonia directly into the surrounding water via special cells in the gills
3
Q
ammonia levels
A
- measured in milligrams per litre or parts per million
- ammonia levels should always be zero
4
Q
effects of ammonia on fish
A
- ammonia causes blood cells to lose the ability to transport oxygen
- damages mucous membranes → causes fish to be susceptible to disease
- damages gill membranes → causes suffocation
- reduced hatch + grow rate
5
Q
nitrite levels
A
- created as a result of bacteria breaking down ammonia
- measured in milligrams per litre or parts per million
- nitrite levels should always be zero
6
Q
effects of nitrite on fish
A
- nitrite causes blood cells to lose the ability to transport oxygen
- causes fish to be susceptible to disease
- causes suffocation
7
Q
nitrate levels
A
- created as a result of nitrite being broken down in the biological filter
- high nitrate level indicates a build up of fish waste
- excessive nitrate provides a nitrogen source for algae
- measured in milligrams per litre or parts per million
- nitrite levels should always be zero
8
Q
effects of nitrate on fish
A
- less toxic than ammonia + nitrite
- affects growth rates + breeding
- causes stress → leaves fish susceptible to disease
- head + lateral line erosion in marine fish
- cichlid hole in the head disease
