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WATER MOLD OR PINK SLIME
Pink slime or pink algae are actually not algae but a bacteria or fungus, often appearing as
streaks or spots in corners and crevices.
Sometimes it appears as a pink or orange colored
ring around the skimmer or waterline. Water mold may have different appearances. It may
appear as raised white spots or as sheet-like growth on the pool's surface. It will have a
slippery feel and may appear as different colors. Water mold is caused by the build-up of a
slime coating produced by microorganisms on exposed surfaces. These microorganisms are
constantly introduced into the environment and will begin to grow when conditions become
favorable (that is, low sanitizer, poor house keeping, etc.). The film that is generated as these
organisms grow makes them particularly difficult to treat as the slime that results affords the
organisms(s) protection from the sanitizer. Water mold is nonpathogenic (does not cause
disease) and, like algae, your pool can be sanitized and safe to swim in with water mold
present. Also like algae, water mold originates from the environment around your pool. One
common way of introducing water mold into a pool is by placing a pool cover on the ground
where it comes in contact with soil that contains the mold. When the cover is placed on the
pool, the mold is introduced into the pool. It is always best to fold a cover and drape it over a
chair or railing. Cold may slow its growth but will not kill water mold.
Regular housekeeping usually keeps water mold and pink slime from growing in your pool. But
there are places in a pool where proper attention is not always given such as behind lights,
under ladder treads, nooks and crannies, a dirty filter, etc. Poor circulation is probably the
biggest culprit. Water mold likes to grow in "dead spots." These are places that water does not
readily circulate to and therefore the water becomes stagnant.
The best overall treatment for pink slime or water mold is to vigorously brush the affected
areas, shock the pool and add a recommended bacteriostat algaecide such as a silver based
algaecide (regular maintenance algaecides may not be effective on pink slime or water mold).
* should not use silver or copper based algaecides- use only the product
recommended in your program. The following tips will be helpful while following the chemical
treatment recommendation provided by your pool professional.
Remove solar cover and discontinue use during treatment.
Vigorously scrub affected areas with a maintenance or algae brush.
Brush all surfaces
very carefully, including the underside of ladder treads and skimmer faces behind pool
lights, etc. Pink slime, in particular, has a gel-like protective coating that resists casual
Increase filter run time to 24 hours if possible to increase circulation.
Continue to maintain your sanitizer level at the high side of normal (free chlorine of 3.0)
during treatment for algae infestation.
Continue to brush walls and vacuum, clean filter as necessary and add maintenance
algaecide until pool is clear of all signs of infestation.
After fighting a stubborn problem such as water mold or pink slime it is recommended that
you thoroughly clean your filter media and disinfect brushes, vacuum head and hoses to
Fresh Start is designed to solve severe
water fouling problems; removing white
water mold and pink slime.
Fresh Start is
compatible with all sanitizing systems
not bleach your pool’s surface.
Click here to watch a short video
Natural Chemistry’s Pool Perfect enzyme
treatment can be used to effectively treat
Water Mold & Pink Slime and is
compatible with all sanitizing systems.
Click here to learn more.