Just trying to figure out what the downside is to having CYA at 70 in our pool. Deciding if I should drain out some water.
Thanks all!
Thanks all!
Isaac-1 said:The problem with a CYA level of 70 is that if algae ever gets established in your pool due to your level of FC dropping below minimum then it will be almost impossible to defeat without substantial water replacement prior to shocking. A low FC event / need to shock can be caused by equipment failure, storm debris, or any number of other unpleasant events. So it is not so much a matter of if it will happen, but when.
Isaac-1 said:The problem with letting your FC get down to 2 ppm with a CYA of 50 is your are risking letting algae get established, the BARE MINIMUM you should ever let your FC down to is 3.7 ppm.
Ike
p.s. almost impossible might be an over statement, difficult, might have been a better choice of words at 70 ppm, almost impossible should probably be reserved for CYA levels over 80-90
Leebo said:Isaac-1 said:I tend to somewhat disagree with this statement. With a CYA level of 70 your shock level will be 20FC....while at a CYA level of 40 it's down to 15FC. In a 10K gallon pool you're only talking about a difference of just over 1/2 a gallon.
ericjdaniels said:I think I may just let the CYA level decrease slowly over time and by water naturally splashing out, hoping it will decrease to around 50.
I concur, with one caveat: never, ever let your FC below he minimum. I did it this way last year, and my personal minimum was the PoolCalculator min + 1. Shocking at 70 would be difficult and expensive.woodyp said:70 is managable for the rest of the summer--fair enough?