Education Technology

Probing an Aquatic Ecosystem

Published on 06/09/2008

Activity Overview

In this activity, students' use a pH sensor and Temperature Sensor to measure and compare the pH and temperature of three aquariums over a period of several weeks. They will compare and understand how plants and animals affect the water quality.They will also understand the effect of changes in pH and temperature on ecosystems.

Before the Activity

  • Plug in Temperature Sensor in channel 1, and pH sensor in channel 2 of the CBL 2; use DIN adapter, if necessary
  • Download DataMate™ program using the TI-GRAPH LINK™ or TI Connect™ software
  • See the attached PDF file for detailed instructions for this activity
  • Print pages 143 - 153 from the attached PDF file for your class
  • During the Activity

    Distribute the pages to your class.

    Follow the Activity procedures:

  • Set up three tanks with water and gravel, allow them to sit for 3 days
  • Let the first tank containing only water be the control tank, mark its water level
  • The second tank contains water and plants (producers) while the third tank contains water, plants, and animals (consumers)
  • Add plants to the second and third tank at an interval of 1 new plant every day for 2 weeks
  • After two weeks add an animal (consumer) to the third tank one new animal every day for 2 to 4 weeks
  • Measure the pH and temperature of each tank every day for a period on 4 to 6 weeks before and after plants and/or animals are added
  • Collect and record all of the data
  • Plot time versus pH graph for the two tanks with organisms and compare the pH values
  • Compare the effect of plants and fish on the pH of a closed freshwater ecosystem
  • Graph the air and water temperature for each tank
  • Understand the effect of changes in pH and temperature on ecosystems
  • After the Activity

    Students' will complete Student Data Collection and Analysis Sheet.

    Review student results

  • As a class, discuss questions that appeared to be more challenging
  • Re-teach concepts as necessary