Is my FC consumption reasonable?

[Water_man]

OK. Already got yesterday's late PM reading. Added chlorine last night (shooting for FC 6.8 as per chem geek's chart) and measured this moring (pump worked non-stop.) Will measure again at eve and will post all numbers. Thanks

Alright, Janet, I have the numbers.
On Thursday, 5/29 at 4:30 pm I had FC 4.5.
I added chlorine at night time an amount calculated to reach 6.8.
After all night of ciruclation, today's 8 AM reading was 6. Today's 7 PM reading was 4.5.
Again, CC has always been <0.5 , although non-zero.
Does it make sense that with CYA 60 I lose 1.5 ppm a day for UV degradation?
Is it possible that FC is consumed by the polyquat?