nitrogen cycle

Question 1

nitrogen cycle

Answer 1

ammonia (NH3) → nitrite (NO2) → nitrate (NO3)

Question 2

what causes ammonia

Answer 2

• decomposition of fish waste
• decaying food
• dead fish
• fish continually excrete ammonia directly into the surrounding water via special cells in the gills

Question 3

ammonia levels

Answer 3

• measured in milligrams per litre or parts per million
• ammonia levels should always be zero

Question 4

effects of ammonia on fish

Answer 4

• 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

Question 5

nitrite levels

Answer 5

• created as a result of bacteria breaking down ammonia
• measured in milligrams per litre or parts per million
• nitrite levels should always be zero

Question 6

effects of nitrite on fish

Answer 6

• nitrite causes blood cells to lose the ability to transport oxygen
• causes fish to be susceptible to disease
• causes suffocation

Question 7

nitrate levels

Answer 7

• 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

Question 8

effects of nitrate on fish

Answer 8

• 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