Re: CYA increasing faster than possible...
When you are doing the CYA test are you standing with your back to the sun holding the tube in front of you looking down into it? You want strong indirect lighting. If you have the tube directly in the sun, you will read lower than the actual amount while if you read it in indoor lighting (unless very bright indirect) then you will read higher than the actual amount. See this link for some photos of the black dot disappearing. You can get 50 ppm CYA standardized solution if you want to experiment with your testing technique.
15.5'x32' rectangle 16K gal IG concrete pool; 12.5% chlorinating liquid by hand; Jandy CL340 cartridge filter; Pentair Intelliflo VF pump; 8hrs; Taylor K-2006 and TFTestkits TF-100; utility water; summer: automatic; winter: automatic; ; PF:7.5
Bookmarks