The Aquarium Nitrogen Cycle

Multiple Choice

What percentage of Earth's atmosphere is made up of nitrogen gas (N₂)?

• 21%

• 78%

• 50%

• 10%

Multiple Choice

Which of the following is NOT a component that nitrogen is a key part of?

• Amino acids

• Proteins

• DNA

• Carbohydrates

Multiple Choice

Which nitrogen compound is least toxic but harmful in high amounts?

• Ammonia (NH₃)

• Nitrite (NO₂⁻)

• Nitrate (NO₃⁻)

• Hydrogen (H₂)

Multiple Choice

What is the process of establishing biological filtration in an aquarium called?

• Cycling

• Filtering

• Cleaning

• Aerating

Multiple Choice

What substances are quickly consumed during the cycling process in an aquarium?

• Oxygen and carbon dioxide

• Ammonia and nitrites

• Salt and sugar

• Chlorine and fluoride

Multiple Choice

How long can it take to complete the cycling process when establishing a new tank?

• Days or weeks

• Weeks or months

• Hours or days

• Months or years

Multiple Choice

What can speed up the cycling process in an aquarium?

• Adding nitrifying bacteria

• Increasing water temperature

• Reducing light exposure

• Adding more fish

Multiple Choice

How can bacterial growth be encouraged in an aquarium?

• By adding more fish

• By providing surfaces to live on

• By reducing water changes

• By increasing light exposure

Open Ended

Summarize the process of maintaining safe nitrogen levels in a fish tank.