5 year old 27,000 gallon vinyl, IG pool, sand filter. (Fixed typo JasonLion)
First 3 years all good, last two can't keep chlorine in pool. Heer's the latest numbers:
Free Chlorine: 0.5 ppm
Alk: 120 ppm
Cyanuric Acid: 50ppm
No matter how much 3" tabs of chlorine or liquid, or shock, same 0.5. I was told by pool place that I am not in chlorine lock.
Any suggestions? I am stumped and actually have water being tested at a Haviland lab for diagnosis. Last year i had pink slime and algae twice(probably due to low chl levels).
Thanks in advance.