My test readings are:
5/24/08
FC-4
CC-0
TC-4
Ph-7.6
TA-120
CH-260
CYA-42
temp-79
5/25/08
FC-3
CC-0
TC-3
Ph-7.6
TA-110
CH-260
CYA-42
temp-80
5/28/08
FC-1.5
CC-0
TC-1.5
Ph-8.0
TA-110
CH-
CYA-
temp-82
6/6/08
FC-1
CC-0
TC-1.5
Ph-8.2
TA-160
CH-240
CYA-55
temp-83
6/10/08
FC-1.5
CC-0
TC-1.5
Ph-7.8
TA-150
CH-290
CYA-43
temp-85
6/14/08
FC-20
CC-0
TC-20
Ph-7.4
TA-110
CH-280
CYA-
temp-85
From 5-24 to 5-25, there was not much change in 24 hours. You can see that 3 days later on 5/28 how the ph goes up. I did do daily checks between 5/28 and the next complete test date of 6/6 to get the Ph down. I just don't record those days that I only do chlorine and Ph. On 6/6 it went up pretty high again, and of course I did add acid to get it back down within range. Again on 6/10 its starting to go up again. I had never shocked my pool until last week. I was hoping that it would kill lots of water bugs, and it didn't. You can see how high my chlorine got on 6'14. I checked this am and my chlorine is down to 5 and my Ph was not bad at 7.6, but my TA was at 130. I added acid this morning because I knew that my Ph would be on its way up. I do have a raised bond beam with two sheer descents so there is alot of aeration. I have a pentair Challenger 1.5 hp pump with pentair triton TR60 sand filter. I have polaris 280 that runs everyday. I use a chlorine feeder with the round pucks.