I am opening my pool, and in a slam phase. plaster 19200gal, chlorine. I started buy adding a gal of liquid chlorine and running the filter and polaris to get the green out. I let the chlorine go to FC 1ppm and showing CC 1. I balanced the ph to 7.4 and started the slam. At this point my CYA measured off the scale low. As in I could fill the test past the 30 mark, all the way to the top at that point. So I entered it as 20 in the app to get started and went into the slam. I ran out of liquid bleach (height of the covid) and couldn't get anything for awhile due to initial lock downs, and life. The pool went back to zero FC and a mild green. Finally I could get something, and decided to get started with trichlor in 3" tabs, a 7 lb tub, since I needed CYA anyhow. So I turned the feeder up to 5 and got to FC 5 in a day and got the green back out. I went through those in about 3 days and was able to get %12 liq chlorine from leslies and another 7lb bucket of tabs. I tested just above the 30 line for cya at this point, but not all the way full. I looked it up and the app said 7lbs of trichlor would add about 22ppm of cya. so I put those in and supplemented with liquid to get to my slam levels. The pool has started looking better. I burned through those tabs in 3 days again. I tested for cya and got a return of 70!??! I really wanted to land right around 50. Can anyone help me understand what has happened. I spent the last year pulling down from very high cya caused by me, before I found TFP, and was so happy to be low. The pool has been beautiful since I have followed these methods. Help??