The strange thing is that last night I added 2.5 try to raise FC,TC to 15ppm at about 6pm (I don't have test kit). This morning I tested 2pm at 9am. then in the afternoon at 2pm. FC, TC back to 0. (these tests were done in the store). This means FC dropped very quickly. I got about 6hours sun during the day. How much bleach do you need in this area ? I saw some post says they add about a jug every other day. This means about 3.5ppm a day. This apparently not enough for my pool. Here are the numbers from this morning at 9am
TC=2
FC=2
PH=7.6
TA=140
HA=220
CYA=60
TDS=800

at 2pm ( I did in Texsun, which use alex testing machine bioguard)
temperature 90
Saturation idx: -0.1
TDS 900
CYA 120 (their reference is 30-200, bioguard system. don't understand)
TC=0
FC=0
ph=7.3
TA=162
Adj.Total Alk=126 (their ref. is 125-150, don't understand)
HA=170
quat=6

Can temperature play a big role in consuming chlorine this quick ?
If so, do it mean that I should probably wait till 8pm to add shock or bleach ?

Thanks.