Pool Stains & staining caused by metals. Colored
MOST, not all, staining on pool surfaces are
preventable. The problem is most people don’t realize they have metals in their
water. Even trace amounts of these metals (iron, copper, manganese, cobalt,
silver) can cause staining.
In fact there’s enough copper in ONE penny to
completely stain an average sized swimming pool! Obviously, the conditions have
to be right. This is where prevention & good, proper pool care come into play.
Here’s what happens: metals come into your
pool whenever fresh, make-up water is added. They’re dissolved in the water.
Whether it’s municipal water or well water, metals can be present.
metals accumulate, the greater the chance that they will eventually come out of
solution. Once out of solution, they make the water cloudy or worse, they
“plate out” on the pool’s surfaces & stain. Metals can come out of solution
through a variety of ways. But there’s 2 that typically happen.
When a pool is shocked whether with chlorine
or a non-chlorine oxidizer, the shock oxidizes everything in the water,
including metals. Oxidized metals become “rust” in the case of iron or “Verdi
gris” in the case of copper.
In the second way, metals come out of
solution or are left “exposed” when the pH, Total Alkalinity and/or Calcium
Hardness are left unchecked & allowed to go low (pH below 7.2, Total Alkalinity
below 80 ppm [non-Pristine Blue pools], Calcium Hardness below 100 ppm). The
water becomes aggressive & the metals are more susceptible to oxidation. In
many cases, pool-owners don’t properly test their water & more likely rely on
the “look” of the water (the water’s clear, everything must be alright). This
is typically the case with blonde hair turning green – low pH helps bring copper
out of solution & “plates” it out on the person’s hair! Then people blame the
chlorine! It’s the copper in the water.
When it comes to testing, remember that you
can only test for metals when they are in solution. Once oxidized, the metals
come out of solution & cannot be tested. That’s why once a metal stain has
occurred, the metal test will NOT show any metals present.
Here’s how to prevent metal stains:
Keep the water balanced. pH 7.4 – 7.6; Total
Alkalinity 125 – 150 ppm (vinyl pools), 80 – 125 ppm (plaster / gunite pools)
(Please note that these TA values ARE NOT applicable in Pristine Blue treated
pools where the TA is to be maintained at no higher than 80 ppm); Calcium
Hardness 200 – 250 ppm (vinyl pools), 225 – 275 ppm (plaster / gunite pools).
In other words, have your water professionally tested at opening, mid-season &
at closing (at least) – make sure they do a copper & iron test.
Prevent metal stains by using
BioGuard Pool Magnet
(a sequestering agent) when filling the pool then adding a maintenance dosage
If you have well-water, treat
automatically with Pool Magnet.
If you have municipal water,
Pool Magnet won’t hurt.
If it’s too late & you already
the water balanced. Keep in mind that further discoloration COULD occur. This
is a temporary phenomena & will clear once the treat process is complete.
light staining of iron & copper, use
BioGuard Pool Magnet
at a rate of 1 qt. per 10,000 gallons of water. For best results, be sure
the chlorine level is 3.0 ppm or less. BioGuard Pool Magnet works well
on “fresh” stains. Avoid shocking the pool for about 3 days.
Jack’s Magic Blue Stuff
is an excellent product. We like Jack’s Magic because you can have high or
higher amounts of chlorine present (in excess of 10.0 ppm). Click here for more
information treating with Jack’s Magic products.
4. If you have a running battle with phosphates - which
feed algae and lead to potentially bad algae outbreaks - use
Naturally Free Stain Remover. Naturally Free does NOT contain phosphonic
acid (a typical ingredient used in almost all metal control products).
metal staining on vinyl, fiberglass or acrylic steps can be treated with Jack’s
Magic Step Stuff.
yourself time, money & effort using Jack’s Magic Stain ID Kit. It really helps
in identifying the exact metal that’s causing the stain.
FREE brochures to learn about
pool care needs & problems.
Some of the information contained in
this article is courtesy of the BioGuard® Chem PLUS 2003, 2004 Reference Guide.