Keywords: stream, wetland, acidity, alkaline, neutral, filter; Grade Levels: first and second grade; Time Required: 45 minutes; Setting: classroom

Goals for the Lesson

  • Students will test stream water at two different locations for acidity.
  • Students will observe and record the type of insects found in stream water at different locations.

Materials Needed

  • Insect Identifying Station
    • water with aquatic insects from two different locations; label the stream water
    • Biotic Index Cards of Aquatic Insects
    • red and blue markers
    • two large plastic containers for stream water
    • magnifying glasses
  • Acidity Station
    • stream water from two different locations
    • red cabbage, vinegar, liquid soap
    • boiling hot water
    • bowl
    • strainer
    • four baby food jars
  • Parent volunteers to help at the stations

State Standards Addressed: E & E Standards: Watersheds and Wetlands (4.1.4)

Subject: science

Topic: the stream


Review what a wetland is and its importance. Explain to the students they will be divided into two groups and rotating through two stations, learning about stream water and the insects that live in the stream water.

Station 1: Identifying Aquatic Insects

  1. Students will observe, identify, and record the insects in the two streams. Students need a key to the aquatic insects, a red marker, a blue marker, and a magnifying glass.
  2. Find an insect in stream water #1. Identify the insect using the key and make a red star by the correct picture. Continue to look, identify, and record your findings for 10 minutes.
  3. Switch to stream #2 and use the blue marker to make blue stars by the insects found in stream #2. Continue looking for 10 minutes.
  4. Bring the group together and list the insects found stream #1 and stream #2. Make observations. Complete a compare and contrast chart.

Station 2: The Acid Test

  1. Students will determine the acidity/alkaline of the two streams by using a chemical indicator.
  2. Shred the red cabbage into a bowl.
  3. Pour boiling water into the bowl. The cabbage color dissolves to make a chemical indicator.
  4. Strain the juice and pour the liquid into four small jars.
  5. Add vinegar to one jar and liquid soap to another jar. Compare the colors. Explain that the red cabbage turns red when in an acid, like vinegar, and green in an alkali, like soap.
  6. Add the two stream waters to the last two jars. Compare the colors to the vinegar and soap jars.
  7. Discuss observations. Draw a picture of what was observed from the two streams and label each picture.


  1. Can a conclusion be made about the water and the insects from each stream?
  2. Check students' drawings and chart for understanding of material.


Sharpe, William E., William G. Kimmel, and Anthony R. Buda. Biotic Index Cards of Aquatic Insects University Park, Pa.: Center for Watershed Stewardship, The Pennsylvania State University.

Gibson, Gary (1996). Science for Fun Experiments. Brookfield, Conn.: Cooper Beech Books.


JoAnne Venturino, first grade teacher, Our Lady of Victory School, State College, PA