Back to school fun
The inverted water bottle
system with variations
Once a classroom has mastered the inverted water bottle system, it’s time to experiment! These school projects ideas are
easy, fun, inexpensive and guaranteed to work.
Light spectrum
Gather three boxes, about 1 ft. x 1 ft. x 1
ft. Cut off the top and the side facing
you. From the florist, purchase 3 ft.
each of red, yellow and blue transparent cello-film. Place the colored
film over the portion of the box you
cut away. Place a plant in each box so
the students can see how each light spectrum affects the plants.
Teachers can also build a box with clear film and place a
straw between the box and the edge of the cello film. Let the
kids exhale into the box. This adds extra CO2 for the plant.
For comparison, have another plant outside the box receiving
regular air.
pH scale highs and lows
This experiment uses three of the inverted water bottle units.
Mix up a gallon of nutrients and add nutrient water to each
unit. Drop the pH of the nutrient water in the first unit to
4.0, make the second unit have a pH of 6.0 and raise the last
unit to the pH of 8.0. This demonstrates the effects of above
optimal and below optimal pH on plants against a
control plant.
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Maximum Yield USA | September 2012
Oxygen content in water
This project uses two bottle units. Give
each student a straw. Have them take turns
oxygenating one of the water bottle units
by lifting the plant and blowing into the water
throughout the school day. This demonstrates the difference
between stagnant water and aerated.
Growing medium and moisture
Using as many bottle units and mediums as the imagination
can hold, put a different growing medium into each of the
units. This shows students that the plant needs oxygen in the
right amounts at the root zone, in addition to demonstrating
how the various mediums hold water differently.
Healthy nutrients vs. junk food
Using three bottle units, mix one bottle unit with nutrient
water, one bottle unit with plain water and one with KoolAid, soda or tea. This demonstrates to students that plants
need specific food and have a specific diet.
These same basic experiments can grow with the students.
As they get older, you can go from a “show and tell” format
of learning to asking them to observe and explain why and
how these experiments worked. They can even get involved
in build-offs.
Hopefully, I have helped inspire you to share your knowledge and creativity as the kids—the teachers of the future—
see garden experiments that work! MY