Hello, I have a question about CYA testing. I have both a TF-Pro (salt) and a Taylor-2006C kit (science dork here). I know the reagents all come from Taylor, and fortunately, all of my results match up when comparing (even the pH, which is a different reagent for each kit). But, the cylinders for CYA make a big difference. The small clear tube from the TF kit reads lower than the dark large block from Taylor. This results in the dot disappearing at a higher number in the Taylor block vs. the TF cylinder. I have checked this in every which way - made new solutions, poured solution from one cyclinder to the other, read indoors, read outdoors. The darkened Taylor block always tests higher. I am currently SLAMing the pool after being on vacation for 2 weeks and was assuming my CYA was 30. But in the Taylor block, it always tests at 40. When I read the results outdoors, the dot disappeared even sooner. This make a difference of 4 ppm for the SLAM chlorine level. If my CYA really is 30, will 16 ppm FC hurt anything? I have been running it at 12 for the past 4 days. Chlorine loss has slowed dramatically and CC has reduced to 0.5 ppm every time I test, but I am still not there. Pool wasn't so bad that I couldn't see my main drains when I returned. It was just slightly green and cloudy. I have an autocover which is why I tend to keep CYA a little lower. I really just want to make sure I am shooting for the right target as far as FC goes for the SLAM.