Other simple hydroponic systems suited to confined classroom
areas can be as simple as a flowering bulb in a glass bulb jar. Since
nobody is present over the weekend to water the plants, other
systems that are great for classroom experiments are small bucket
float or raft systems. These use a polystyrene board to support
small plants floating in a bucket or pan of nutrient solution (additional aeration via a small aquarium air pump is an optional
extra that can teach students the importance of oxygenation to
root systems).
A wide range of basic hydroponic systems are well suited to classroom crops.
A small cooler box and plastic tray can be turned into a hydroponic
system at little cost.
More advanced experiments and science
fair projects
Experiments like placing plants in different positions around the
classroom, in sealed and unsealed containers, in a dark cupboard
and under a lamp, or indoors and outdoors allows students to
evaluate how light, temperature, moisture, wind and protection
can affect hydroponic growth. Later on, experiments can become
more advanced. Looking at the effects of gravity on plant growth
is a classroom favorite; simply invert a bean seedling grown in
rockwool and watch gravitropism occur. Examining phototropism as seedlings bend toward a light source is also popular.
Science fair projects involving hydroponics can range from the
very simple to highly advanced depending on the age and ability of the student. Usually some assistance is required for these
projects because they are dependant not only on a good idea, but
also sound technical and scientific skills. Hydroponic science fair
experiments need to include each of the following:
• An idea to be tested (e.g., the effect of water source on hydroponic plant growth).
• Some treatments to apply (e.g., rainwater, pond water, tap
water, well water, distilled or pure water).
• Replication—Experiments involving plants needs more than
one plant for each treatment. Ideally, there should be at least
four plants or more for each treatment being tested, and one
of these should be a control. Or, there should be a group of
plants that are untreated (e.g., four plants are given rainwater,
four are given pond water and four plants are given distilledwater as a control).
• Results recorded (e.g., measurements of plant growth, plant weight,
observations in plant color, root length, photos and drawings)
• Experimental conclusions—While advanced science fair experiments are expected to do some statistical analysis and interpretation, most students should be able to calculate mean scores or
averages for their measurements and make accurate statements
about each treatment as compared to the control plants.
Remember, science fair judges favor hydroponic experiments
that are fully planned, follow all the rules of science experiments,
have well-grown plants and have a good understanding of what
caused the results observed. MY
Maximum Yield USA | September 2012
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