Have been gone from Western Pa for over 10 days thus the reason no reply .Im now ready for help and to become part of the BBB user group. Pool is inground 21500 gals-DE-Vinyl lined.Is crystal clear but still cannot get a good chlorine reading. I have purchased a HTH Chemical Test kit so here we go. Yesterday after being gone 10 days took readings with kit
Chlorine 1.0 PH 6.8 Total Alkalinty 170 Total Hardness 220 CYA 40 My readings
Free Chlorine 0 Total Chlorine 0 PH 6.5 Total Alkalinty 186 Total Hardness 205 CYA 110 Phosphate 2000 - Pool Store 1
Free Chlorine .3ppm Total Chlorine 1.3 ppm Combine 1.0 PH 7.1 Hardness 190 Alkalinty 182 CYA 60 -Pool store 2
So you can see all on the same pool water with no treatment between some difference
I added (1) bottle of Phosphate remover but as comared to when adding a bottle initially 4 weeks ago the filter never really loaded up .I question the 2000 reading
Today added 1.5 gals of Muriatic Acid and nothing else.Water still clear and up to 80 in temp ,Side Chlorinator is on and loaded with 3 inch tabs.Took another reading with my kit just now
Chlorine 1.0 PH 6.8 Alkalinty did drop from the acid 120 Hardness 240 CYA 52

Everything is clear but still issue of the chlorine reading.

What additional info do you need to assist ? The pool store 2 try to get me to switch to Pristine Blue .I prefer after reading to try the BBB. Wait for your reply