The Effects on Humans From Algae in Swimming Pools
- In nature, there are many different types of algae, which are extremely small plant forms. In fact, they're so small you'd need a microscope to see individual algae. Like most any plant, algae makes use of photosynthesis to absorb sunlight and create the energy needed to live. In swimming pools, the three most common varieties are green, yellow and black algae. And because algae loves sunlight and water, it can thrive in a swimming pool it's managed to contaminate.
- Pool-specific algae aren't themselves harmful to humans if they're ingested. Algae will, however, make a frightful-looking mess out of a pool. Slimy skin, smelly hair and a really bad taste in the mouth are the minor issues pool algae cause. More importantly, algae dissipates available chlorine, leaving none left to fight off bacteria. Algae also excrete waste products that the bacteria Escherichia coli thrives in. Found in fecal matter, E. coli in pool water swallowed by swimmers can cause potentially deadly infections.
- Algae can make its way into any pool via several different routes. Wind and rain often deposits them in a pool. In addition swimmers carrying algae on their feet or their swimsuits can track them into a pool. And it only takes a very small amount of algae in a poorly sanitized pool to quickly cause problems. If a pool's lacking adequate chlorine levels algae will rapidly reproduce, creating large, dirty looking algae blooms almost overnight.
- The best method for handling algae in a swimming pool is to prevent them from gaining a foothold at all. It's vital that disinfectants like chlorine or bromine be maintained at recommended levels. For chlorine, 2 parts per million (ppm) is best, with a range of 1 ppm to 3 ppm being acceptable. Also, pool pH needs to be at 7 to 8, with 7.4 to 7.6 being ideal. Chlorine works best when pH is also balanced.
- If algae appears in a swimming pool, there are two solutions. The first is chlorine shocking. It involves raising pool chlorine levels to about 20 ppm and then letting them decline back to about 2 ppm. Repeat shocking is often needed. A second algae elimination solution requires the use of an algaecide. Often used in conjunction with shocking, algaecides kill off pool algae. A thorough scrubbing of pool surfaces and vacuuming up of dead algae after shocking and algaecide application is recommended.