All,
I've read on TFP that the ideal FC level should be roughly >=7.5% of CYA (e.g., FC = 6, CYA = 80, 6/80 = 7.5). I've also read in a few threads that the sanitation effectiveness is the same regardless of the FCppm as long as it's in the same ratio (e.g., 3/30 = 5/50 = 7/70) but as CYA goes up other problems, such as higher chlorine costs and prohibitive SLAM requirements.
So...why does the FC/CYA chart (for SWG pools) need CYA to be up in the 60,70,80 range? If I set my CYA to 30 and maintain FC at 3, I'm over that effective ratio and should have good sanitation with reduced chlorine production from the SWG, right? I appreciate some clarification and I apologize if this has been addressed in other threads - I've read a few and didn't get this question quite answered. It just seems that if we can get a clear pool at consistently lower levels, costs go down.
Thank you.
I've read on TFP that the ideal FC level should be roughly >=7.5% of CYA (e.g., FC = 6, CYA = 80, 6/80 = 7.5). I've also read in a few threads that the sanitation effectiveness is the same regardless of the FCppm as long as it's in the same ratio (e.g., 3/30 = 5/50 = 7/70) but as CYA goes up other problems, such as higher chlorine costs and prohibitive SLAM requirements.
So...why does the FC/CYA chart (for SWG pools) need CYA to be up in the 60,70,80 range? If I set my CYA to 30 and maintain FC at 3, I'm over that effective ratio and should have good sanitation with reduced chlorine production from the SWG, right? I appreciate some clarification and I apologize if this has been addressed in other threads - I've read a few and didn't get this question quite answered. It just seems that if we can get a clear pool at consistently lower levels, costs go down.
Thank you.