G
Guest
I have several dark patches on the bottom of the deep end of my in-ground pool. I noticed them last year, and they were still there this spring.
I am meticulous about proper levels and cleaning. However last year, while on vacation, the chlorine level dropped to 0 for a few days.
I have brushed and shocked (to 20). I tried rubbing a chlorine puck on the stains, with no effect at all. I treated with polyquat a few days ago. Could these be stains instead of algae growth?
Thanks for any help!
Levels and info:
TC: 7
FC: 7
pH: 7.4
TA: 90
CYA: 30
CH: 180
Borate: 30
Copper: 0
Liner: vinyl
17,000 gallons
DE filtering
Pump on 14 hours a day since May 15
I am meticulous about proper levels and cleaning. However last year, while on vacation, the chlorine level dropped to 0 for a few days.
I have brushed and shocked (to 20). I tried rubbing a chlorine puck on the stains, with no effect at all. I treated with polyquat a few days ago. Could these be stains instead of algae growth?
Thanks for any help!
Levels and info:
TC: 7
FC: 7
pH: 7.4
TA: 90
CYA: 30
CH: 180
Borate: 30
Copper: 0
Liner: vinyl
17,000 gallons
DE filtering
Pump on 14 hours a day since May 15