The Beginner's Guide to the Nitrogen Cycle for Aquariums Quiz

What does the nitrogen cycle in aquariums primarily involve?

• Oxygen production by fish

• Conversion of fish waste into food

• Evaporation of water

• Photosynthesis in plants

Which nitrogen compound is the most toxic to fish?

• Nitrate

• Ammonia

• Oxygen

• Nitrite

What is the role of beneficial Nitrosomonas bacteria in the nitrogen cycle?

• It eats fish

• It eats nitrites and produces nitrates

• It eats ammonia and produces nitrites

• It produces ammonia

How can you remove nitrates from an aquarium?

• By doing a water change and adding plants

• By adding more fish

• By increasing the temperature

• By reducing light exposure

What does 'cycling your aquarium' mean?

• Feeding fish twice a day

• Changing the water daily

• Ensuring enough biological filtration is present

• Cleaning the aquarium glass

What happens if you suddenly add many more fish to a cycled aquarium?

• The ammonia levels will decrease

• The beneficial bacteria may not be enough to handle the waste

• The water will become clearer

• The fish will stop producing waste

Where do beneficial bacteria grow in an aquarium?

• Only on the fish

• Only in the filter

• Only in the water

• On every surface, including gravel and decorations

What should you do if your aquarium's nitrate levels reach 40 ppm or more?

• Remove some dirty water and replace it with fresh water

• Add more fish

• Increase the temperature

• Add more fish food

What is the primary benefit of nitrogen fixation in for plants?

• It helps in the decomposition of organic matter.

• It increases soil alkalinity.

• It converts nitrogen into a form plants can use.

• It reduces soil erosion.

The diagram in the image represents the nitrogen cycle in a student's aquarium. Ammonia, nitrites, and, to a lesser degree, nitrates can be harmful to fish. The student wants to keep the nitrogen in this aquarium cycling normally without having to continually change the water.

Which of the following should the student add more of to help remove the nitrates and improve the natural cycling of nitrogen in this aquarium?

• Fish

• Plants

• Nitrobacter

• Water