Diatoms obtain food by making it themselves during a process called photosynthesis. Diatoms are single-celled organisms of the family eukaryotic algae, a type of plant with cell nuclei. Diatoms are found in both freshwater and saltwater, and more than 16,000 species thrive in rivers and oceans.
Photosynthesis is the process by which all plant cells make food, including diatoms. Photosynthesis takes the energy from a light source, converts it into chemical energy and stores it in sugar in the plants. Sugar, water and minerals are collected by the diatoms and converted to glucose bonds, which are later used for all the cellular activities required by the diatoms.