I had gone over to test the water for a friend whose daughter will be having a party on Saturday. We tested the FC and the TF100 Test kit color was a light orange/dark orange which after reading could have a FC level between 10 and 20 & dark orange is between 15 and 30. PH was @ 7.2. CYA was @ 90.
After reading a bit it could be a chlorine lock. What next? Is the pool sanitary? Will the FC naturally drift down. They were using pucks and I asked them to get rid of them as they were in the skimmer. Pool is old (like 20 years). One main drain, one return & one skimmer. Sand Filter with a black pump. Water clarity is clear. Someone came over and used powdered shock that has trichloro-s-triazinetrione with 65% chlorine 4 all in one (something). It looks like the person put in at least 3 lbs. if not more of the powdered shock?
So what is next for the person as I need to help them. Or am I way off base. TA was 120 during the testing. We did not test for anything else.