My CYA is running high, 100+, so I am prepping for a drain refill soon once I get some equipment problems sorted out. I had a discussion with a pool store clerk, hence posing the question here, where he stated that the CYA was mostly at the top of the water and that I should therefore pump the water from the top of the pool when trying to lower CYA. So, is this pool store babble or is there anything to it? I have not seen anything like that on the forum.
On a related note, I notice a lot of people having trouble reading the CYA when it's over the 100 mark on the tube, myself included. The scale is logaritmic so it's not an easy read. Sorry if that is obvious to most, I just hadn't seen any cautions regarding guestamating numbers over the 100 mark.