I took over my pool in January of 2013 and installed a SWG. With help from this forum, I got everything set up and had a successful first year (am having some black algae show up recently).
Lately I've noticed FC levels are dropping faster and figured I need to clean and/or replace my SWG cell. But since it's been awhile, I decided to go ahead and do a full chem test.
pH 8.0+ (lowered again to 7.2, my pH always drifts high due to SWG).
CYA 0 ????
The CYA test is what really shocked me. I did this test repeatedly last year while trying to dial in my CYA to around 60, and am confident I am doing it right. I'm filling the test tube all the way to top and am barely noticing any clouding of the black dot.
My salt seems to fall relatively quickly too. We get a lot of rain and evaporation, but I didn't think these things were supposed to change CYA (or salinity). Splash out shouldn't be a major issue in my pool as most of the swimmers are less than 5 years old.
Is a leak the only explanation? I might have added a little water two or three times last year, but generally evaporation and rain balanced each other out.
My pool test kit (Taylor K-2006) are a little over a year old and have been kept indoors in the dark. Is it possible CYA reagent is bad?