Pursuant to my post in January, I am finally trying to remedy the "algae tub". I am SO GRATEFUL for all of the posts that helped me even believe it is MIGHT be possible to make this pool swimmable. I am on day three of the journey, and now I have questions.
As recommended, I purchased the Taylor K2006 testing kit. I did not drain, but the evaporation was enough that there would be a moderate quantity of fresh water in the swamp. I have been testing FC and shocking from 6am-dark every day, brushing and skimming as much as I can see/reach, cleaning the filter about five times a day, running 24/7.
The first day, I found the CYA 30, so I used the pool calculator to shock, shock, shock, every half-hour to hour. It did not seem to maintain a shock, but the FC registered, when the original shock left it at 1.5 after an hour.
Day two: at least the mystery larvae appeared dead, and the pool was a less ominous shade of green (not so bright).
Until the early afternoon, even dumping copious amounts of bleach would quickly register only a moderate FC level (4-6). Eventually, I found myself with only two small bottles of bleach left, so I just tossed what I had in while I waited a few hours for my husband to come home with more. I figured - if it's not shocking, at least there is FC in there, so I shouldn't lose ground in a few hours...
...then, a mysterious thing happened. After a few hours, I tested again to see how far behind I was, and the FC was "off the charts". (I stopped counting drops after 18ppm.) The water was all foamy (which it had been the initial few hours, but only off and on afterwards).
Day three: The same not-so-bright green (not foamy), and the FC still tests "off the charts", and I only put in two bottles of bleach in in past 20 hours (pH 7.8 - I can't get a reading for CC, either).
Is this normal/ explainable? I don't want to stop shocking and lose ground to the algae, but I don't want to waste chemicals, or damage from supershock. (I had bad directions from the pool store when I tried to clean last fall, and it was a very expensive start-over, not to mention the time spent.) This just doesn't seem right - to jump from average to to super-shock without adding bleach.
Thank you in advance for any words of advice!
13k gallon (24ft round AG)
Hayward CC1500 100gpm cartridge