My boss at work asked me to check out his pool as he had been having issues with it for several years. I told him about TFP and that I had a Taylor test kit. He has an approx. 13,000 gallon fiberglass in-ground with a sand filter, .7 hp motor, inline auto Dichlor chlorine feeder. So, I go to his house yesterday after work and after testing get the following results;
Water was very clear and by appearance alone everything looked good, but…
CC 11.0 !!!
CYA way above 100! (The dot disappeared after only about 3/8” of water in tube, way below the 100 mark)
I have been reading this forum since I installed my pool last spring and I have yet to see test results anything like I have here. He has had this pool about 10 years and said he struggles with it every year, from cloudiness to wall staining from metals and said this year he’d like to get on top of it. I thought I’d be able to go there and give him my recommendations from all I’d learned here at TFP, but in all honestly these test results left me scratching my head. To top it off, he took his water to 2 different pool stores and they both told him his CYA was 30. I know pool store results can be wrong, but to both be wrong by the same amount has him wondering which test is correct, the pool store or the Taylor. Considering he has been using Dichlor for many years and has never done a drain/refill I am pretty confident my test is the accurate one but anyway, assuming it is, what are we likely dealing with here? Ammonia maybe? He has added over 24 gallon of 10% liquid chlorine over the last several days in an attempt to get a chlorine reading with his test strips (I told him to get a good test kit) but from what I can tell it quickly becomes combined chlorine and the Free Chlorine reading stays low. Being that the water is completely clear yet the readings are so out of whack, I am a bit stumped. Any advice is appreciated!
Edit: Does CYA testing reagent go bad over time? Mine kit is about a year old.