LaMotte Pool & Spa Owner's Handbook - Manual (Page 18)

ALGAE (continued)
COLOR GREEN ALGAE BLACK ALGAE MUSTARD ALGAE
APPEARANCE Pea green color.
Sometimes colors
entire body of water.
Also attaches to pool
surfaces. Better known as
“black spots” on pool
walls & surfaces. A yellow film usually
found on steps or
walls.
CAUSES Insufficient or inactive levels of sanitizer. Inadequate water
circulation. High nitrate and phosphate levels.
TREATMENT 1. Check pH &
adjust if necessary.
1. Brush affected
areas thoroughly.
1. Brush affected
areas thoroughly.
2. Shock treat pool
water.
2. Spot treat affected
areas with
sanitizer.
2. Spot treat affected
areas with
sanitizer.
3. Brush surfaces if
necessary.
3. Shock treat pool
water & later add
algicide.
3. Shock treat pool
water or use a
specialized mustard
algae treatment.
4. Retest pH &
repeat treatments
if necessary.
4. Brush & vacuum as
necessary.
4. Retest pH &
repeat treatments
if necessary.
Notes:
1. Always consult a pool professional first if any treatment procedures
are unfamiliar.
2. Regular algicide treatments are recommended for outdoor pools that
experience persistent algae problems.
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