Phytoplankton are microscopic plantlike organisms that are invisible to the naked eye. These microscopic plants make their own food using nutrients from breaking down organic wastes. Phytoplankton provide direct and indirect energy sources as the base of the food chain. They grow in abundance in ecosystems in the sea. You can also grow your own for a school science project or for your own personal use by following a few simple steps.
Put 0.5 kg of potting soil in a 1-liter container and cover it with 500 ml of sea water. Heat the mixture with steam (do not boil) in a vegetable steamer on two consecutive days for 2 hours each time.
Pour off the excess water after the soil settles. Heat the saved water to 73 degrees C again on two consecutive days. Put the remaining product (the soil and the water mixture) into a sealed flask.
Start a phytoplankton culture by pouring 250 ml of the nutrient solution into a 500-ml flask. Using an eyedropper, collect some phytoplankton algae from the ocean and put it into the flask. Seal the flask with a piece of cotton.
Keep the flask under a fluorescent light. Keep it away from bright and direct sunlight. Shake the flask regularly to keep the phytoplankton from sticking to the sides or settling on the bottom.
Once the mixture begins to grow, it will change color and appearance. Increase the chances of the phytoplankton's survival by placing the flask in the refrigerator.