I am super mini!

In our oceans and in all freshwater habitats you can find little siblings of our plants. They are called microalgae and are so small that you can only see them with a microscope.
Like their big siblings, the plants, algae can use the energy of sunlight to produce sugar with the help of photosynthesis. In a simple experiment you can check whether algae are present in a water sample.

Algae need sunlight to grow and with a little patience you can establish just in a few days your own little algae culture breed.


    Experimental setting

    • Fill 2 glasses with some water from a pond or pool
    • Add about 1 teaspoon of liquid fertilizer to each glass and screw the glasses shut
    • Place one glass in a sunny place (e.g. on the windowsill), the other glass in a dark place (e.g. in the cellar)




    • Even though we could not see them, there were tiny little algae in the water sample
    • Due to the nutrients (fertilizer) and the sunlight the algae could grow by photosynthesis. Now we can see them (the water is greenish)
    • In darkness there was no photosynthesis and therefore no growth (the water remains light)

    You need

    • 2 glasses with screw caps
    • 2-4 ml of liquid fertilizer
    • A water sample from a pond or pool
    Heinrich Heine University
    University of Cologne
    Max Planck Institute for Plant Breeding Research
    Forschungszentrum Jülich