I reported earlier this summer about some 'dirty staining' going on in my pool. I am 99.999% certain this is NOT algae, but laziness on my part on not brushing enough. My figures have been solid all summer (see below) & water looks great. All I can say is that regular Brushing of the walls/bottom does NOT remove this 'dirty stain'. But a Magic Eraser definitely cleans it - and leaves a scrub line from the eraser.
We'll likely be unable to swim (too cold water) in about 3 weeks so I was thinking of doing a Shock treatment of the pool in hopes to totally eliminate any chance of organics causing this. So looking for some guidance on my options. (are there more than 1, like JUST a ton of Chlorine bleach?) PS - went on 8 days vacation 2 weeks ago. Dumped (4) Gallons of 12.5% Chlorine in before leaving. FC was 1.5ppm when we returned. I immediately bumped it back up to 5.0ppm
So, my questions for the experts:
1 - is it normal to do a yearly "shock" treatment? (I have NEVER done one in the year of having it freshly re-surfaced (fiberglass spray on))
2 - Would the better method be the SLAM approach?
3 - Could I just dump in Algaecide (polyquat???). (e.g., Leslie's pools)
4 - Absorbic Acid treatment?
5 - what might you recommend or point me to in PS ? My biggest concern is that anything I do NOT harm the Fiberglass surface.
FC = 5.0
CC = 0.0
CYA = 45 (I think. But you know how THAT goes! Could be 40)
PH = 7.5
CH = 225
TA = 80
Thanks in advance !