LaMotte Pool Manager Water Quality Handbook - Manual (Page 37)

Ideal Ranges
Pools and spas: <10 ppm Nitrate
Pools and spas: <100 ppb Phosphate
Algae
Color
Green Algae Black Mustard Algae
Pea green color,
sometimes colors
entire body of water.
Also attaches to
pool surfaces.
Better known as
“black spots” on
pool walls and
surfaces.
A yellow film, usually
found on steps or
walls.
Cause
Insufficient or inactive levels of sanitizer. Inadequate water
circulation.
Treatment
• Check pH and
adjust if necessary.
• Shock treat pool
water.
• Brush surfaces if
necessary.
• Retest pH and
repeat treatments
if necessary.
• Brush affected
areas
thoroughly.
• Spot treat affected
areas with
sanitizer.
• Shock treat pool
water to 30 ppm
chlorine and later
add algicide.
• Brush and
vacuum
as necessary.
• Brush affected
areas thoroughly.
• Spot treat
affected areas
with sanitizer.
• Shock treat pool
water and later
add algicide.
• Retest pH and
repeat treatments
if necessary.
Note: There are a number of specialized algae treatments on
the market. If the problem is persistent, ask a pool professional
about these.
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