Hello new dude and Jess. My oclt was good one day and then I checked it and not good the next day. I can't pass the quarter test in the deep end. I understand I should keep doing slam at 20 PPM for a 50 cya. But how long can I do this without causing any damages to my above ground vinyl liner that is 18 years old. Should I just keep slamming until I can see the quarter? Appreciate your help. I love keeping it at the 20 because the pool is just so Crystal Clear it's amazing but I'm afraid I'm going to hurt my liner keeping it that high for so long. I am into this slam since the 8th. Should I have any concerns or just keep doing it until I can see that darn quarter? Thanks againDO not stop slam until your pool looks like this...Link-->How Clear is TFP Clear?
AND you pass OCLT. Link-->Overnight Chlorine Loss Test
AND your CC<=.5