Key Findings In Our Experiment

1. We found out that the Cabomba Plant grows best under white/natural light.

2. During the last experiment, we found out that the Cabomba Plant grows best under green light, instead of white / natural light.

3. The Cabomba Plant grows the worst under blue light.


1.All the colours of the rainbow have different wavelengths. For example, violet has short wavelengths, while red has long wavelengths. Visible light appears as white light because it is a mixture of all the colours. Also, chlorophyll is the principal pigment involved in photosynthesis.

2. Chlorophyll absorbs all the different coloured wavelengths, but leaves green as the colour it reflects and as the colour we see. Therefore, white light is best to grow plants under because green light doesn't do much of anything for photosynthesis.

3. The wavelength in which chlorophyll works best is in the red and blue range, and therefore does not absorb the green wavelength which is why the leaves appear green.


Through our experiment we discovered that there are different rates of photosynthesis that occur in different light conditions with the answer to our question, we also discovered that our hypothesis was wrong.
We initially thought that the plant grows best under red light. But after our experiment, we realised that the white / natural light grows best instead.

Areas To Improve

  1. We could keep the rest of the Cabomba plants in sunlight as over the time the Cabomba Plants slowly died out.
  2. We need to repeat the experiment more times to ensure reliable results
  3. We have to make sure each time we redo the experiment, we record data at the same time interval


What is photosynthesis?
Photosynthesis is the process of converting light energy to chemical energy and storing it in the bonds of sugar. Robert Emerson discovered two light reactions by testing plant productivity using different wavelengths of light. With the red alone, the light reactions were suppressed. When blue and red were combined, the output was much more substantial.(wiki pb works) ( the naked scientist)

Who else did our experiment?
After researching previous experiments done on this topic, I found a similar experiment done by three scientists in Colorado in 2003. These scientists used three different colors to our two, red, blue, and green. They were also testing to see which of these lights would allow plants to photosynthesize the fastest. 
The way we did our experiment is by placing the Cabomba Plants in a beaker with a test tube on the top and place it in a box. Inside the box, we had set a light source up with four different colours: Blue, Red, Green and White / Natural light.

Areas for further studies
There are some of the scientists who did our experiment. They then placed a light over the plant and ran three separate tests for each colour measuring the amount of CO2. They thought that the blue light would use the most C02 because blue light absorbs the most light and the most energy and C02 is used in photosynthesis, but their results proved otherwise. Their results showed that blue used the least amount of C02, red used the medium amount of C02, and green used the most C02.

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