Moderator comment: This post was separated out from this thread: CYA Level...
How much is "too much"?
I did an OCLT last night. Zero drop in FC over 8 hours. CC is 0.5 or less (the sample turns the faintest shade of pink and that could be debated) one drop knocks it crystal clear.
So, here are my test results last night, repeated exact at 6:30 a.m. this morning: FC=4.5, CC=0.5; PH=7.5; TA=100; CA=350; CYA=30.
Okay on that last, I have tried three or four times, the results vary between just below but close to the 30 line and half-way between 30 and 40 but closer to 30. It depends on the angle and height I hold the tube.
Back to the point of my question - CYA. At 6:30 this morning, 4.5 on the Chlorine and at 1:30 this afternoon it is down to 2.0. I am in north Texas (Dallas area) and my pool get a lot of direct overhead sun with zero shade. Basically, the house faces slightly south of east so by 9:30 a.m. the sun is directly pointed at at least 75% of my pool. By 10:30 until sun down, all sun. If my past results are any indication, my chlorine will be less almost but not quite zero by 6:30 this evening (lets call that a 0.5 FC). If it make any difference, my pool is shallow at 5' 4" in the center, 3' 2" on the ends (bedrock is good for house foundations, bad for pool diggers) and the pool warms up really easily when the clouds make no appearance.
Do I need to run my CYA up more, or is this pretty "typical"? Should I simply run FC up to 6 at night instead of 4.5? Will starting with higher FC actually matter or will the burn off remain the same until I change CYA concentration?
How much is "too much"?
I did an OCLT last night. Zero drop in FC over 8 hours. CC is 0.5 or less (the sample turns the faintest shade of pink and that could be debated) one drop knocks it crystal clear.
So, here are my test results last night, repeated exact at 6:30 a.m. this morning: FC=4.5, CC=0.5; PH=7.5; TA=100; CA=350; CYA=30.
Okay on that last, I have tried three or four times, the results vary between just below but close to the 30 line and half-way between 30 and 40 but closer to 30. It depends on the angle and height I hold the tube.
Back to the point of my question - CYA. At 6:30 this morning, 4.5 on the Chlorine and at 1:30 this afternoon it is down to 2.0. I am in north Texas (Dallas area) and my pool get a lot of direct overhead sun with zero shade. Basically, the house faces slightly south of east so by 9:30 a.m. the sun is directly pointed at at least 75% of my pool. By 10:30 until sun down, all sun. If my past results are any indication, my chlorine will be less almost but not quite zero by 6:30 this evening (lets call that a 0.5 FC). If it make any difference, my pool is shallow at 5' 4" in the center, 3' 2" on the ends (bedrock is good for house foundations, bad for pool diggers) and the pool warms up really easily when the clouds make no appearance.
Do I need to run my CYA up more, or is this pretty "typical"? Should I simply run FC up to 6 at night instead of 4.5? Will starting with higher FC actually matter or will the burn off remain the same until I change CYA concentration?
