Hi all, once again have to start off by thanking everyone for the great advice here. Really enjoying being a pool owner this year! Anyway, my CYA has been about 100. Have confirmed this by adding tap water to sample and testing again like I was told here. So through heat and heavy use (kids can't seem to keep water in the pool) I have had to add water to the pool several times this year. I tested for CYA again yesterday (twice, did not believe numbers first time) and found my CYA to be 70. I need some reassurance here, I am quite confident in the number but with that will I reduce my free chlorine levels and want to stay away from....well you know the A word (algae)!!