I have been fighting this older pool since we moved here two months ago. It was full of sludge and green! We brushed and cleaned up what we could see and then called pool service company for help. They tossed in what I now know to be Cal Hypo and it helped the algae but water was cloudy. Then I called the previous owner and he told me to fill the automatic chlorinater with the 3" tablets. BIG MISTAKE! My search was on and I found this website. Thank you all so much! Bought ColorQ test kit (was using strips) and found that everything was out of balance! So I followed TFP recommendations and all is pretty good now. I'm skipping some steps as I'm sure you've heard it all before. Yes, CYA was off the charts. Drain, refill, drain, refill, etc etc.
Present day...all tests taken at 7am (pool temp 85) ColorQ and TF100 test results:
FC 3.62 (TF100 about the same)
TC 3.62 (TF100 about the same)
PH 7.3 (TF100 about the same)
TA HELP ColorQ #1 229 #2 193 #3 179 (same water, clean test tube) TF100 130!!!
CH 405 (TF100 550)
CYA 78 (TF100 60)
I know what to do for the FC/TC obviously
PH lowered with 2 lbs PH minus to lower TA last night---aerating now to raise
CH is high but if I drain/refill my TA will go up (I tested our well water...TA is high)
What to do?? Yes, I use Pool Math religiously!!