White Water Mold

White Water Mold (WWM) is a naturally occurring fungus (this is NOT a form of Algae; it is animal not vegetable) that resembles white mucous or tissue paper found all over pool surfaces.

WWM forms a heavy, protective coating providing the organism with an unusually high level of protection that is very resilient against halogen-based (chlorine, bromine) & non-halogen sanitizers or germicides.

wwmWhite Water Mold is a biofilm.

WWM can remain a contaminant even after treatment.

WWM exists on the surface of PVC plastics

WWM can re-contaminate long after it appears that it has been destroyed (includes pool toys, floats, ladders, steps, fountains, automatic pool cleaner parts, skimmer baskets, weirs, directional fittings, garden hoses, etc.)

WWM – small quantities can lead to a re-establishment of the problem

WWM is caused by improper water & pool maintenance, environment, poor circulation

WWM prefers areas that are “dark” (not exposed to direct sunlight) & with “slow moving” water

WWM is not caused by using Biguanides (Soft Swim, Baquacil, Polyclear, etc.)!

REMENBER: WWM is an environmental issue.


  1. Prevention of “white water mold” is preferred over treatment. Follow these steps to help prevent white water mold:
  2. Physically brush & clean ALL Pool surfaces weekly, including ladder steps (especially underneath each step) & rails
  3. Expose ALL pool surfaces to as much sunlight as possible (sunlight & UV are natural
  4. Remove the lid from the skimmer to allow sunlight into the basket for several hours each day ** Inground POOLS MUST USE EXTREME CAUTION in doing this in order to avoid a person falling into or otherwise injuring themselves due to an open skimmer.
  5. Regularly add oxidizing chemicals into the skimmer to purge & clean the filtration lines of any bio-film*
  6. When adding make-up water from the garden hose, allow the water to run for 2 to 3
    minutes before putting the hose into the pool.
  7. Regularly clean pool toys & floats (use Stow Away)
  8. Regularly clean pool solar blanket (use Stow Away)
  9. Chemically clean pool filter every 4 to 6 weeks (use Strip Kwik, Kleen It or SoftSwim® Filter Cleaner)
  10. Add regular Maintenance dosages of “Shock” & Algicide every 2 to 3 weeks as prescribed
  11. Use Optimizer Plus® as a preventative measure
  12. Run the filter a minimum of 12 hours daily to prevent “dead spots” in the pool
  13. Remember to clean & rinse the brushes, hoses & vacuums that you use to clean the pool
  14. Leave as much of your pool equipment exposed to the sun
  15. Keep the water balanced at all times.
  16. Recheck after heavy usage or rain or large “top-offs” of new water.
  17. Water balance refers to Free Available Sanitizer level, pH, Total Alkalinity, Calcium Hardness.


  1. Treatment of “white water mold” MUST BE QUICK AND TOTAL! DON’T SKIMP!
  2. Clean all pool & affected surfaces as prescribed above.
  3. Physically clean & remove all visible “white water mold”
  4. Add an initial dosage of Algicide to the pool*
  5. “Shock” the pool with a triple or quadruple dose*
  6. Run filter 24-7 until water is clear & halogen or peroxide levels are at the “higher” level
  7. Chemically clean the filter
  8. Bring in a fresh water sample about 4 days later for a retest & evaluation
  9. Maintain Optimizer Plus® levels
  10. Maintain good water balance of pH, Total Alkalinity & Calcium Hardness