Over the past 4 years have never had any problems that were so confusing that we could not easily fix. Have used test strips, and a test at our local pool supply every month or 2 to validate our strips were close.Last month I used the link here and purchased a Taylor K2006C kit to test with and have been using the BBB method since the first week of April of this year taking samples to our local pool store and comparing results with the test kit(very close). We recently went on vacation for a week and came home to a slightly cloudy pool while we were away had 3+ inches of rain and a lot of leaves, bugs , and debris in the pool . Cleaned and shocked to 35PPM and turned crystal clear, now a few days later is very cloudy again. I leave the pump run all the time because I haven't set up a timer for the pool heater/pump yet, and maybe because I figure it won't hurt anything.. My current results of testing are PH=7.4 FC is 4.5 CC=0 Alkalinity =120 CYA=80 Temp =90F, my wife added some chlorine while I was at work today because she said the pool was cloudy, even though it was at 2.5 PPM yesterday. Am I mistaken in thinking that since I have no CC that I could possibly have a sand filter problem? Haven't opened it since we put it in. Any advise would be greatly appreciated. Thanks and try and have a great night. I work 12 hour days and am getting ready for bed, but will check back tomorrow afternoon, I am not ignoring anyone, I just have to get some sleep.