Hello, all.
Short question up front: What percent reduction in CYA is reasonable for a given percent of pool water exchange if Delta T is very close to zero?
With all the rain that Northern CA has gotten I'm tackling a water exchange to reduce CYA (currently about 150, maybe higher).
My fill water (55 F) is only about 4 degrees cooler than the pool water (59 F) so I expect Delta T is not significant (800 salt, 440 CH so please correct me if I'm wrong). Still, I'm drawing from a shallow step while filling to the bottom opposite end 40 feet away. I have a good pump and strong supply and am able to exchange at 50 gpm.
If I target 100% exchange (15 hours) should I expect CYA to come down by 50% (since there will be some amount of blending as Delta T is low)? I really don't have any experience here and am appreciative of any that you may provide.
I'd prefer not to stop once I start, and I'd rather overshoot and hit a lower CYA, but at the same time don't want to needlessly spend $ on more new water than necessary.
Of course, if I don't get it low enough and have to exchange more, it's not the end of the word.
Thanks,
Matt
Short question up front: What percent reduction in CYA is reasonable for a given percent of pool water exchange if Delta T is very close to zero?
With all the rain that Northern CA has gotten I'm tackling a water exchange to reduce CYA (currently about 150, maybe higher).
My fill water (55 F) is only about 4 degrees cooler than the pool water (59 F) so I expect Delta T is not significant (800 salt, 440 CH so please correct me if I'm wrong). Still, I'm drawing from a shallow step while filling to the bottom opposite end 40 feet away. I have a good pump and strong supply and am able to exchange at 50 gpm.
If I target 100% exchange (15 hours) should I expect CYA to come down by 50% (since there will be some amount of blending as Delta T is low)? I really don't have any experience here and am appreciative of any that you may provide.
I'd prefer not to stop once I start, and I'd rather overshoot and hit a lower CYA, but at the same time don't want to needlessly spend $ on more new water than necessary.
Of course, if I don't get it low enough and have to exchange more, it's not the end of the word.
Thanks,
Matt