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Water What-ifs

Teacher Notes,
Lesson Extensions and
Alternative Assessment Ideas

Teacher Notes, Lesson Extensions and Alternative Assessment Ideas

Lesson 1-Does the increased use of fertilizers effect biodiversity?

1.10% fertilizer solution

Add 10 grams of a granular houseplant food such as Peter's Special to 90 milliliters of distilled water. Store in a capped bottle. Invert and mix before use. Put in labeled dropper bottles for use in this lesson.

2. 20% fertilizer solution

Add 20 grams of a granular houseplant food such as Peter's Special to 80 milliliters of distilled water. Store in a capped bottle. Invert and mix before use. Put in labeled dropper bottles for use in this lesson.

3. Nitrate test kits (Chemical), Nitrate test strips, Phosphate test kits (Chemical) and Phosphate test strips, can be ordered from a scientific supply company.

Note: Safety goggles and aprons should be worn at all times when mixing reagents.

    Lesson 2-Does an increase in nitrate and phosphate levels effect the growth of algae?

1. 10% nitrate/phosphate solution

Add 10 grams of a granular houseplant food such as Peter's Special to 90 milliliters of distilled water. Check to make sure the food contains both nitrates and phosphates. Store in a capped bottle. Invert and mix before use.

2. 20% nitrate/phosphate solution

Add 20 grams of a granular houseplant food such as Peter's Special to 80 milliliters of distilled water. Check to make sure the food contains both nitrates and phosphates. Store in a capped bottle. Invert and mix before use.

Lesson 3-Does the use of increased amounts of fertilizer accelerate seed germination?

Note: Students should have completed Lesson 1 before beginning Lesson 3. This will familiarize them with the dissolved oxygen test kits and also give them a basic understanding of how dissolved oxygen effects aquatic organisms.

1.10% fertilizer solution

Add 10 grams of a granular houseplant food such as Peter's Special to 90 milliliters of distilled water. Store in a capped bottle. Invert and mix before use. Put in labeled dropper bottles for use in this lesson.

2. 20% fertilizer solution

Add 20 grams of a granular houseplant food such as Peter's Special to 80 milliliters of distilled water. Store in a capped bottle. Invert and mix before use. Put in labeled dropper bottles for use in this lesson.

3. Seeds can be purchased at a local garden center, department store or grocery store.

4. Coffee filters or paper towels may be used in place of filter paper.


Lesson Extensions

1. Research higher percent concentrations of fertilizers and determine how increases effect different variables such as macroinvertebrate biodiversity, algal growth and seed germination.

2. Have each group use a different type of seed and determine if the seed types vary in there response to increased concentrations of fertilizer solutions.

3. Have students research different types of fertilizers and determine which ones have the greatest effect on different variables such as macroinvertebrate biodiversity, algal growth and seed germination.

Note: Peter's Special House Plant Food has: 15% Total Nitrogen 30% Phosphoric Acid 15% Total Potash

Contact a local farmer or farm store and ask for fertilizers with differing concentrations of these three components.


Alternative Assessment Ideas

1. Set up several different aquatic ecosystems. Add differing concentrations of a fertilizer solution. Have the students keep a daily journal of the changes which take place over a period of time.

2. Have student assess the quality of several different water samples and determine the levels of nitrates and phosphates in each sample.

3. Teach students to perform chemical tests such as a nitrate and phosphate determination. Assess their ability to conduct these tests accurately by providing known samples for them to analyze.



Water What-ifs Home | Nitrate/Phosphate Lessons



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Last Modified: 7/27/00

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