(Chlamydomonas, Chlorella, Euglena, Closterium, Anacystis)
Planktonic algae look like pea-soup or spilled paint.
Planktonic algae may at first appear as if your pond water is changing color. As these green or blue-green algae bloom more they can cause your pond to look like pea soup or spilled paint. Planktonic algae will also cling to things such as your shoreline and leave traces of scum on rocks or other objects in the water.
Many different species of planktonic algae can be present at once, and they can change over time depending on temperature, nutrients, light, and more. Some forms of planktonic algae are toxic and can only be identified with the proper equipment.
Planktonic algae can be found anywhere.