Answers to Basic Pool Questions

Yellow (Mustard) Algae

What is it?

Mustard algae is a chlorine-resistant form of green algae that often resembles dirt or sand on bottom or sides of pool. It contains compounds that act as a defense mechanism against the oxidation efforts of sanitizers, helping it survive even in highly chlorinated conditions. This factor can even create a large chlorine demand in certain situations. Mustard algae can be brushed away very easily, but returns quickly.

To kill mustard algae:

5 steps to prevent algae growth:

  1. Maintain a sanitizer​ residual of 1-3ppm
  2. Do an initial and weekly application of a preventative algicide (such as Algae Complete®)
  3. Shock routinely
  4. Make sure there is adequate circulation and filtration
  5. Brushing​ surfaces is vital

Do you have a problem that you don’t see listed?

Your local BioGuard Dealer can help you diagnose and solve your problem! Stop by with a water sample to get started.