Billion Oyster Project

How Does Water Get In and Out?


Nitrogen Cycle Investigation



Class Periods




Subject Areas



Students explore the water cycle within their classroom tank.  Then they compare their tank to the estuary.


  • Describe how water can get into and out of their classroom tank.

  • Compare the water cycle in their tank to the water cycle in the estuary.

Materials and Resources

Student Handouts


  • Student models from the previous lesson, A New York City Water Cycle

  • 10 wide-mouthed, clear bowls/jars

  • 10 small jars

  • Plastic wrap

  • 10 Rubber bands

  • Ice cubes (optional)

Before you get started


  • Be sure that you have the students’ models of the water cycle from the previous lesson, A New York City Water Cycle.

  • A couple of hours before class, you may want to prepare a bowl of water for an evaporation demonstration. Fill a glass bowl (or wide-mouthed jar) with hot water. Place plastic wrap over the top of the bowl and secure with a rubber band.  Set in the direct sun, if possible. If you want to speed up the evaporation and condensation, place the ice cubes on top of the plastic wrap.

  • To make the demonstration more complex and more similar to the classroom tank, you may also prepare a second bowl in a similar way, but cover it only partly.  Most classroom tanks are not completely covered, or are not covered all the time, so preparing a partly-covered bowl could raise interesting issues for discussion.

Instruction Plan


  1. In small groups, students review their water cycle models from the lesson, A New York City Water Cycle.

  2. Students look around the classroom: What parts of the water cycle can you see in the classroom and out the window?

  3. Discuss together and make a list of their ideas.

    • Are there any water cycle components that exist in the classroom that are not on your water cycle model?

    • Which parts of this water cycle could have an impact on your oyster tank?

  4. Students get Our Tank’s Water Cycle handout.

  5. As a group, the students decide upon the appropriate arrows, labels and other additions in order to complete the diagram.

  6. As a class discuss the following:

    • How does water get into and out of tank?

    • Is there a complete cycle in the tank? Or only part of a complete cycle?  Or is there a complete cycle sometimes, depending on how we set up our tank?


  1. In this activity student groups will create their own evaporation / condensation / precipitation water cycle.  

  2. Each group gets a wide-mouthed, clear bowl/jar, a small jar, water, a piece a plastic wrap and a rubber band.

  3. Place the small jar in the large bowl/jar.  Fill the large bowl with water about 2/3rds of the way up the small jar. Place plastic wrap on top of the bowl.  Secure plastic wrap with the rubber band. Write student names on the side of the plastic wrap with a marker.

    • Note: particularly if your classroom tank is only partly covered, you might suggest that some groups could choose to only partly cover their bowls.  There could be an interesting comparison with groups that choose to cover their bowls completely.

  4. Place the bowl in a sunny location.

  5. Check back next class to see how much evaporation and condensation took place (on the plastic wrap) and how much precipitation took place (in the small jar).

  6. Extension: Students mathematically determine how much water evaporated out of the bowl and precipitated into the cup and how much could evaporate out of the classroom oyster tank.

  7. Extension: Design a system for the top of the tank that captures the most amount of water (evaporation and condensation) and replaces it (precipitation).


  1. In this activity students (as individuals or in small groups) look again at their water cycle models from, A New York City Water Cycle and consider how their models compare to a water cycle in the estuary.

  2. What is missing from their models that need to be part of the estuary water cycle?  What is in their models that does not belong in the estuary’s water cycle?

  3. What are the inputs and outputs of water in the estuary?

  4. Is there a complete water cycle within the estuary?  Or only part of a complete cycle?  Or is there a complete cycle sometimes or in some places, depending on local conditions?

  5. Students sketch an estuary water cycle on a blank piece of paper with arrows and labels.


  1. What else goes into and out of the tank?  The estuary?  

  2. If we think of the tank as a model for the estuary’s water cycle, what are the strengths of this model?  What are the weaknesses of our tank as a model for the estuary’s water cycle?

  3. What other kinds of things cycle through the water, air, earth and living things?

  4. Is there anything, any substance, any type of matter on Earth that does not cycle through water, air, earth, and/or living things?

    • If everything must eventually cycle, why must that be the case?  

    • If you can think of something that doesn’t cycle, how is that possible?  

    • That means it has to arrive on Earth from somewhere else, or leave Earth at some time. (How?)   OR

    • That means it never moves or changes form at all.  (Why not?)

  5. Explain: In Nitrogen Cycle Investigation we will be looking at the nitrogen cycle in depth, as it has a major impact on the functioning of organisms and ecosystems in the tank, in the estuary, and around the world.


NGSS - Cross-Cutting Concepts

  • Energy and Matter

    • Matter is conserved because atoms are conserved in physical and chemical processes.

NGSS - Disciplinary Core Ideas

  • ESS2.A: Earth’s Materials and Systems

    • All Earth processes are the result of energy flowing and matter cycling within and among the planet’s systems. This energy is derived from the sun and Earth’s hot interior. The energy that flows and matter that cycles produce chemical and physical changes in Earth’s materials and living organisms.
  • LS2.B: Cycle of Matter and Energy Transfer in Ecosystems

    • Food webs are models that demonstrate how matter and energy is transferred between producers, consumers, and decomposers as the three groups interact within an ecosystem. Transfers of matter into and out of the physical environment occur at every level. Decomposers recycle nutrients from dead plant or animal matter back to the soil in terrestrial environments or to the water in aquatic environments. The atoms that make up the organisms in an ecosystem are cycled repeatedly between the living and nonliving parts of the ecosystem.

NYC Science Scope & Sequence - Units

  • Grade 6, Unit 4

    • Interdependence

NYS Science Standards - Major Understandings

    • Matter is transferred from one organism to another and between organisms and their physical environment. Water, nitrogen, carbon dioxide, and oxygen are examples of substances cycled between the living and nonliving environment.