This document discusses metals that can contaminate pools, including copper, iron, and manganese. Copper and iron most commonly come from corroding heat exchangers, source water, or off-brand chemicals, while manganese primarily comes from source water. When metals come out of solution in the pool water, they can cause stains or discoloration. To treat for metals, the document recommends removing any surface stains, applying a sequestering agent to prevent new stains, filtering the pool water with a filter aid to remove metals, and regularly cleaning the filter to manage metals over time.

1. BIO203: METALS
Pool & Spa University

2. METALS IN POOLS
➤ Metals are less common than algae or cloudy water, but they can be tougher to treat.
➤ Metals can find their way into the pool from a few sources.
➤ Some source water contains metals; if you suspect metals in your source water,
have it tested for metals. If it tests positive, have a filter installed, if possible.
➤ Corroding equipment can deposit metals into the water. Heaters with copper
exchangers are a common culprit; when acidic water passes through the heat
exchanger, it can start to pit, with the dissolved copper moving into the main
body of the pool.
➤ Off-brand chemicals can be especially sensitive to changes in sanitizer and pH,
causing the metal in them to fall out of solution.
➤ When metals come out of solution, they will tend to present as clear, discolored
water. Eventually, stains can form on the surface of the pool as more metal starts to
build up on the surface.
➤ There are three metals that pool owners deal with: copper, iron, and manganese.

3. Left: iron staining on pool surface. Right, top: copper in pool water. Right, bottom:
approximation of manganese in pool water.

4. COPPER
➤ Copper is one of two common metals found in pools; in addition to coming
from corroded heat exchangers and source water, many off-brand algicides
contain copper that comes out of solution when water balance changes.
➤ The age of a heat exchanger is irrelevant when it comes to corrosion; if
acidic water flows through the exchanger for an extended period of time—
weeks or months, generally—it will corrode the exchanger.
➤ Some homes have copper piping that has corroded over time due to low
alkalinity and pH; if possible, have the customer use water that does not
flow through these pipes or install a pre-filtering system.
➤ When copper comes out of solution, it can present as green, gray, or a bright
blue.
➤ Copper will come out of solution in the presence of an oxidizer (shock);
however, it will also come out of solution in the presence of some balancing
chemicals if added in large quantities.

5. IRON
➤ Iron is one of two common metals found in pools; it tends to
come from source water, although old, corroding equipment or
the use of non-stainless-steel clamps and screws can add iron
to water.
➤ Stainless steel clamps and screws, when exposed to low pH
and high chlorine for extended periods of time, may rust.
Never use clamps in the main pool body.
➤ When iron comes out of solution, it can present as green (in
very small quantities), orange, or brown.
➤ Iron will come out of solution in the presence of an oxidizer
(shock). It does not usually come out of solution in the
presence of balancing chemicals.

6. MANGANESE
➤ Manganese is a rare metal found in pool water. It comes from source
water.
➤ When manganese comes out of solution, it will present as red or purple;
once out of solution, it can gradually change to chocolate brown or black.
➤ Manganese will come out of solution in the presence of an oxidizer
(shock). It does not usually come out of solution in the presence of
balancing chemicals.
➤ The treatment for manganese is different from the treatment for copper
and iron. Refer to ALEX® Pro instructions for how to properly treat
manganese.
➤ If you encounter a system containing manganese, stress to the
customer the importance of installing a pre-filtering system to manage
manganese.

7. TREATING FOR METALS
➤ You should be testing for copper
and iron with every water test
when water quantity allows.
➤ Ask the customer questions
regarding water quality. What color
is the water? Is the water clear?
➤ Note that green, hazy/cloudy
water is likely not metals.
➤ If the color is red or purple, test
for manganese.
➤ Inquire as to any stains present in
the pool and their age. Older stains
are harder to remove. Ask about
the color of these stains as well.

8. TREATING FOR METALS - COPPER AND IRON
➤ Begin by removing any stains from the surface with Stain
Treat or Erase® Iron Stain Remover. Stains should lift quickly.
This does not remove the metals from the pool, just from the
surface.
➤ Apply Pool Magnet® Plus to the main body of the pool.
Circulate for a minimum of 15 minutes. This will grab onto
the metals, preventing them from staining surfaces. Note that
this does not remove the metals from the pool; if the metals
are not removed from the water, the Pool Magnet® Plus will
eventually wear off and cause staining and discoloration
again.

9. TREATING FOR METALS
➤ Pre-mix and add Sparkle Up® through the skimmer to coat
the filter media with the Sparkle Up® mixture. This will filter
out metals as the water passes through the filter. Circulate for
a minimum of 24 hours.
➤ Note: Sparkle Up® is a filter aid. If filter pressure increases
8-10psi above clean pressure before 24 hours have passed,
backwash (sand filter) or take out and rinse filters
(cartridge).
➤ After cleaning the filter with water, chemically clean the filter
with Kleen It® to remove residual metals and Sparkle Up®
from the filter.

10. MANAGING METALS
➤ For owners who cannot pre-filter source water, regular use of Pool
Magnet® Plus can help prevent metals from causing stains in the
pool.
➤ Quarterly filter cleanings using Sparkle Up® and Kleen It® can
remove any metals that Pool Magnet® Plus has sequestered.
➤ The use of a CuLator® packet in the skimmer can passively filter out
metals over time.
➤ Avoid using off-brand algicides and sanitizers containing copper.
➤ Perform weekly checks of water chemistry with a test kit or test
strips; ensure that pH is within the acceptable range. Test in-store
monthly.
➤ Check metals on every water test.

11. CONGRATULATIONS!
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