Bacteria
Bacteria and Fungus Stains
Some types of bacteria and fungus found in the soil can
actually penetrate through a vinyl liner and cause stains to appear
on the liner. Usually they will start off as spotted or cloud-like
formations on the liner. Algaecides used in the pool water
have little if any effect on the stains caused from bacteria, since
it doesn't get to the source of the bacteria in the soil. If a pool
is known to have a problem with bacteria staining the liner, the
ground underneath the liner may be treated with a solution of one
half household chlorine bleach and one half water. Mix the bleach
in the water and mist the floor of the pool with a small garden
sprayer three or four times prior to dropping the new liner in the
pool. After the last application of bleach solution, wait several
hours before dropping the liner; making sure the solution has been
absorbed into the ground.
If the liner has been recently replaced, one method
which has been used several times is the use of Copper Iron Sulfate
(FeSO4) to change the pH of the soil around the pool, therefore
killing off the source of the bacteria or fungus. This is
not a guaranteed cure in all cases but in the last few years it has
had some astonishing results for some of our customers. Best of
all, this can be tried without having to drain the pool and replace
the liner! Copperas Iron Sulfate is a chemical used by tree
nurseries for treating the pH of soil for some iron deficiencies in
plants. For an average size pool, say an 18 x 36 rectangle, you
need about twelve to fifteen pounds of this powered chemical.
Sprinkle it on the ground next to the pool deck on as many sides of
the pool as possible. Then turn a lawn sprinkler on the ground for
two or three days, long enough to get the ground around the pool
thoroughly saturated with water. The idea is to get the powder to
soak deep into the ground so it can change the pH of the soil and
hopefully kill off the source of the bacteria. Usually results are
not seen for a week or two since it has to get deep in the ground
to have any effect on the bacteria. The Copper Iron Sulfate has not
been known to have any harsh effects on grass and care should be
taken when using around delicate flowers.
