I am new to the forum. What brought me here was a recommendation of a friend when I told him that I have been using chlorine tabs and my CYA is really high. I am trying to avoid draining my pool. The CYA is testing around 110 and my local pool store told me that it was OK. My chlorine tested at 5.7 and they are telling me that is OK as well. However, they are saying I should be in that range ideally. The CYA/FC chart states my FC should be closer to 12 or so. That seems so high but the explanation makes sense. I don't want to have to replace water to lower by CYA but raising my chlorine to 12 makes me nervous. As a side note, I bought bleach and am not planning on using chlorine tabs any more. Thanks in advance.