1. Terraqua Columns


Students discover what ecosystems are by exploring the relationships between him/herself, other living things, and the student's environment. Students create and study miniature ecosystems by building a terraqua column - a 2 story soda bottle tower with soil and plants on the top and a water source on the bottom. The terraqua columns will be used throughout the ecology unit for practice with water and soil quality monitoring and with making and recording observations. Later in the unit students can conduct independent investigations with their terraqua columns.


Can define ecosystem and ecology
Can identify a personal ecosystem
Can build a terraqua column



Terraqua Column
Terraqua Column from Bottle Biology


Attachment Size
1terraaqua_column.doc 54.5 KB

1. Terraqua Columns - Logistics

30 min ecosystem lesson and discussion
20 min build terraqua column frame
20 min add soil, water, and seeds
* I recommend building the terraqua column frame on one day then adding the soil, water, and seeds the following day.

2-3 students

For each group:

  • 1 clear 2 Liter soda bottles
  • 1 foot wick (1-2 cm wide strip of old cotton towel)

For 2-3 groups to share:

  • Awl OR electric drill with 3/8 inch bit
  • Hole punch
  • Box cutter
  • Scissors
  • Sharpie marker

For whole class to share:

  • Soil, either store-bought potting soil or soil from outside
  • Hand trowel
  • 1 package radish seeds OR Wisconsin Fast Plant seeds
  • Water, either tap water or pond/creek water
  • Graduated cylinder


  • Rubbing alcohol (for erasing sharpie marker lines)
  • Clear tape


1. Terraqua Columns - Background

Teacher Background
Understanding ecosystems is the basis for all of the study of ecology. Students are introduced to the idea of an ecosystem by examining his or her interactions with other living things and the environment. The terraqua column that students build becomes the foundation for the following weeks of exploration of water, soil, living things, and the environment.

Bottle Biology contains a wealth of information about the terraqua column project and further directions to explore. Definitely check out the Bottle Basics section to learn about working with soda bottles and also the Terra Column section for everything you wanted to know about building, maintaining, and studying terraqua columns. This site has a much more detailed step-by-step building guide complete with diagrams and troubleshooting.

Student Prerequisites

1. Terraqua Columns - Lesson Plan

Ecosystem lesson and discussion

  1. On a blank sheet of paper, ask each student to draw a small stick figure in the middle of the page to represent him/herself.
  2. Instruct students to write down as many living (or formerly living) things that you interact with in your daily life in the space around the stick figure. Connect each thing to the stick figure with a line. You may want to start an example on the board for students to build from. Think about family, friends, teachers, other people, pets, food, plants, garbage, etc. Give students at least 5 minutes to create a diagram.
  3. Around the diagram, draw or describe the environment in which these interactions take place. You may want to add to the example on the board. Think about home, school, the outdoors, the city, the neighborhood, etc.
  4. Spend 10-15 minutes discussing and sharing the diagrams that students created. Focus on the interactions between a student and the other organisms and on the interaction between a student and his/her environment. You may want to introduce the term "organism" as a living thing. Some questions to encourage discussion:
    • How many interactions did you come up with? Are there more?
    • What interactions did everyone have in common?
    • What interactions did only some people have?
    • What kind of interactions do you have with living things? With non-living things?
    • Can we group interactions together into categories?
  5. Tell students that their diagrams illustrate their personal ecosystem. Encourage students to help come up with a definition of an ecosystem. Ecosystem - a group of organisms that interact among themselves and with the environment in which they live
  6. Describe other ecosystems (a forest, a meadow, a mountain) and the interactions that occur between organisms and between organisms and their environment. Consider both small (a fish tank) and large (planet Earth) ecosystems.
  7. Conclude the discussion with the question: Are we all part of the same ecosystem? Is someone in Asia part of our ecosystem?


Terraqua column construction

  1. Explain that students will be building mini-ecosystems called terraqua columns. Give students an overview of what they will be doing with their terraqua columns over the next 2-3 weeks.
  2. Divide students into groups of 2 or 3 students. Once students are seated with their group, distribute 1 soda bottle and wick to each group. Distribute terraqua column building kits around the classroom so that materials can easily be shared.
  3. Remove the label from your soda bottle.
  4. With a Sharpie marker, draw a line around the bottle 2 cm below the shoulder curve (where the bottle curves towards the opening). You will want to visually make sure that the students drew their lines in the right place.
  5. Use the box cutter to poke a slit along the line.
  6. Use scissors to cut the rest of the way around the line. The larger, bottom part of the bottle is your "reservoir". The smaller, upper part of the the bottle is your "planter".
  7. Use the hole puncher to punch 2-3 holes near the upper rim of the reservoir. The holes allow air to circulate in the water portion of the terraqua column. This is not as necessary if you intend to use tap water.
  8. Poke a 1 cm hole in the cap with an awl or drill a 3/8 inch hole with an electric drill. To save time or improve classroom management, this can be done ahead of time by the teacher.
  9. Use a Sharpie to label the reservoir with the names of the group members.

Filling the Terraqua Column

  1. Saturate the wick in water.
  2. Insert the wick through the hole in the cap. Screw the cap onto the opening of the bottle.
  3. Invert the planter onto the reservoir. Make sure that the wick reaches all the way from the bottom of the reservoir to the top of the planter.
  4. Add water to the reservoir. I found that 500 mls was a good amount of water. If you want students to monitor the water level and learn about measurement, you can add water to the reservoir in 100 ml units and mark the side of the reservoir with a sharpie at the top of the water line.
  5. Add soil to the planter. When adding the soil, hold the end of the wick up and fill in the soil around the wick. Make sure that the wick is not stuck against the side of the planter. Bury the top of the wick in the soil.
  6. Plant 5 seeds in the soil.
  7. Water the soil with 100 mls of water.
  8. Have students make initial observations of their terraqua columns. You may want to record:
    • Amount and type of water added
    • Number, type, and location of seeds planted
    • Type of soil added
    • Color and texture of soil
    • Color of water
  9. You may want to tape the planter and reservoir together with clear tape.

1. Terraqua Columns - Assessments

Create an ecosystem diagram for an animal of your choice. Be sure to include interactions between your animal and other organisms AND between your animal and its environment.

Going Further

  1. Conduct soil analysis on the planter part of the terraqua column. See Soil Analysis lesson.
  2. Conduct water quality assessment on the reservoir part of the terraqua column. See Water Quality lesson.
  3. Conduct an independent investigation using terraqua columns. See Terraqua Column Experiment lesson.
  4. Study the life cycle of plants from seed to germination to maturity and flowering to the production of new seeds. Use Wisconsin Fast Plants as part of the Raising Plants lesson.