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Water You Learning About PH?

What makes water healthy? One way we can determine the health of a body of what is by looking at its PH, a measure of how acidic it is. Test the PH of some water near you and explore more about water health!

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Plan

  • How will you test the PH of the water?
  • What water will you test? Are there any bodies of water near your meeting area like a lake or pond? If not, what about a stream or a storm sewer?
  • How might the different bodies of water you test differ?
  • Will you test tap water as a control to see how it compares to untreated water?

Do

With your Section, or in a small team, check the PH of some bodies of water near you.

  • The easiest way to do this is using PH test strips – these are commonly used for swimming pools and can be found at any store that sells pool supplies (specialty stores, Canadian Tire, etc.).
  • Follow the instructions on the package – usually you will hold the strip in the water and swish. Then, compare the strip to the container. What is the PH of the water?
  • To make this into a true experiment, compare the water – try testing it at different times of day (see if a Scouter can go by on a weekend morning and do a test), test different areas of the water, or go back and test again at a different time of year. What happens if you test before and after a rainfall?
  • At your meeting place, test a cup of regular tap water. How does the PH compare to the PH of the water you tested?
  • Human activity can change the PH of water – try this on a small scale by adding things to different cups of water then testing the PH.
    • Use different cups of water – test the PH of your control (regular) cup of water and write it down. Then add different things to try to make the water more acidic or basic. Test each cup after you’ve added to it.
    • To make the water more basic, try adding baking soda
    • To make the water more acidic, try adding milk, lemon juice or vinegar.

Review

  • Were the PH levels of the water different? Did any of them surprise you?
  • Animals need water with a PH between 6 and 9 in order to survive. If the PH of a body of water is below 6, it will start impacting everything in an ecosystem (plants, animals, etc.).
  • What did you learn about how human actions affect PH? What actions might impact the PH of water?

Materials

  • PH test strips (can be found in a pool supply store or aisle)
  • Cups
  • Tap water
  • Materials to change the water’s PH, like lemon juice, vinegar, milk, baking soda, etc.

Keep it Simple

  • Start small by learning about how sensitive water is and how you can change the PH of water by only doing the second part of the experiment (collecting tap water in cups and adding different materials to change the PH).

Take it Further

  • Test the PH of a nearby body of water over a longer period of time – test it at different times of day, in different conditions (after a rainfall, while the snow is melting, etc.) or during different seasons. Compare your data – when does the PH change?