- microscopic plants deposited in pool or spa water by wind, rain and dust, they thrive in sunlight and warm water, clogging pool equipment and causing slippery surfaces and green water; there are 21,000 known species of algae
- algae are not disease causing, but can harbor bacteria, and it is slippery
- most common pool types are black, blue-green, green and mustard (yellow or drawn)
- pink or red-colored algae-like organisms exist but are bacteria and not algae; maintaining proper sanitizer levels, shocking and superchlorination will help prevent algae occurrence
