I think I may have solved the issue of grey results. I was at 4.5FC. I added 4G of 12.5% to get to 35-40. However, the regional packager of 12.5% is a few towns away. So what if effective CL was much higher than 12.5? Maybe it took me to >50ppm FC? The 2006 is accurate to only 50, right? Maybe that's what happened....???? Just a thought. If so, good thing her liner is already shot!