HI
Not sure if it's "black algae"...
We have a blackish shadow on porous rocks above the waterline, but I think it's affecting the FC/CC levels.
I did a SLAM ending in an OCLT of 0.6ppm and CC of 0.
The brand new jandy SWCG is set at 50% and is "maintaining" FC at 7 (I'm deliberately keeping it on the high-side because of the rocks). But the CC is creeping up and has got to 1.2 in only 12 days.
The pool looks great! Nothing below the waterline. The skimmer baskets are clean, the filters are new and the SWCG is less than 1-month old. I use TF-100 test kit. We even switched out the Polaris bag.
Recent levels are:
FC 7
CC 1.2
pH 8.0 (before 3/4 gallon of Acid)
TA 90
CH 350
CYA 70
Salt 3400
Temp 83F
Is there a homemade bleach spray we can use on the rocks - that's the only thing I can think of that's causing the rise in CC.
Not sure if it's "black algae"...
We have a blackish shadow on porous rocks above the waterline, but I think it's affecting the FC/CC levels.
I did a SLAM ending in an OCLT of 0.6ppm and CC of 0.
The brand new jandy SWCG is set at 50% and is "maintaining" FC at 7 (I'm deliberately keeping it on the high-side because of the rocks). But the CC is creeping up and has got to 1.2 in only 12 days.
The pool looks great! Nothing below the waterline. The skimmer baskets are clean, the filters are new and the SWCG is less than 1-month old. I use TF-100 test kit. We even switched out the Polaris bag.
Recent levels are:
FC 7
CC 1.2
pH 8.0 (before 3/4 gallon of Acid)
TA 90
CH 350
CYA 70
Salt 3400
Temp 83F
Is there a homemade bleach spray we can use on the rocks - that's the only thing I can think of that's causing the rise in CC.