Basic Steps to Kill Algae

Algae is not likely to form fiberglass pools as they have smooth surfaces, but can happen when introduced by a foreign source. For example, it enters the water on swimmers or by wind, rain, and pool accessories.

Green Algae – Most Common and easiest to kill. Spreads quickly and will vary in severity.

Yellow Algae – aka brown or mustard algae, rare and found in humid climates. Looks like globs of pollen or sand clinging to the shady corners of your pool.

Black Algae – Is not algae, it is a Bacteria which digs into porous surfaces; therefore, the roots are hard to kill. This also makes it unlikely in a fiberglass pool. Can be very irritating to human eyes and ears.

Red Algae – most harmful to humans! Not algae, it is a bacterium. Can cause serve illnesses.

To better serve you, please contact a professional service before attempting the following steps.

Green and Yellow Algae Removal Steps

• Vacuum walls and floor – Manually vacuum your pool on your filter’s waste setting. Bypasses your filter, preventing recirculation of contamination. Unless the filter is already contaminated then start with cleaning and sanitizing the filter. Pay special attention to areas of with algae. Replace water as it is lost keeping water level at half skimmer level.
• Brush walls and floor – helps chlorine get deeper in the remaining and loosens contaminates so they can be killed and filtered out. Nylon brush for fiberglass.
• Test and Balance Water – balancing water chemistry ensures your sanitizer is effective on the algae. High pH or low alkalinity makes sanitizer ineffective.
• Shock – this super-chlorinates the water and kills algae. Follow package instructions to determine the dose per pool size, depending on the algae you may have to double or triple the dose.
  1. Green Algae – might need a double dose of shock
  2. Yellow Algae – might need triple the dose of shock
     1. Shock the pool at dusk or night as sun likes to eat chlorine before it kills the algae, put cleaning equipment in shallow end to sanitize.
     2. Run filter overnight to circulate the shock

• Repeat brushing and shock process again if algae remains.
• Filter Out – Dead algae will be gray and your pool water will be cloudy blue, filter needs to be run until water is clear.
• Test and Balance water – Check levels of everything and balance water chemistry. Alkalinity, pH, chlorine, cyanuric acid and calcium hardness need to work together at correct levels to maintain a crystal-clear pool.
• Clean the filter – kill the microbe spores. Deep clean filter cartridges or replace them entirely. Sand or D.E. filter will need to backwashed.

Note: an algaecide may become necessary if you’re fighting more chlorine-resistant algae, such as mustard algae or black algae. Even then, the pool algaecide should work with chlorine or other sanitizers – not as an alternative to them.