When the metals have deposited on the pool surface, they aren't in the water any more. The metal level in the water can't go down to really and truly zero, but it can get close enough that the test can read zero.
Blue/Black algae on walls & floor
- Thread starter jt-cali
- Start date
Reviving the thread...
I changed 2/3 of my pool water 4 weeks ago to lower the CYA and start fresh. I have shocked the pool at mustard level and kept the FC between 4-6 afterwards.
FC=6 CYA=25 pH=7.4 TA=90 CH=210
I haven't seen any progress with my stain/algae and thought I'd give Polyquat 60 a try. A quart should be enough for the initial dose and one maintenance dose. Is that enough time/doses to see if it helps? Or do I have to continue with the maintenance doses for several weeks before ruling it out? Want to know how much I should order before starting the regimen.
I changed 2/3 of my pool water 4 weeks ago to lower the CYA and start fresh. I have shocked the pool at mustard level and kept the FC between 4-6 afterwards.
FC=6 CYA=25 pH=7.4 TA=90 CH=210
I haven't seen any progress with my stain/algae and thought I'd give Polyquat 60 a try. A quart should be enough for the initial dose and one maintenance dose. Is that enough time/doses to see if it helps? Or do I have to continue with the maintenance doses for several weeks before ruling it out? Want to know how much I should order before starting the regimen.
I am almost certain these are metal stains, not algae. The combination of mustard algae shock level and brushing the pool will remove any kind of algae at least temporarily. If your markings remained through that, they aren't algae.