Thank heavens for this website, which has helped my family manage our pool for the last several years! But we recently had an equipment failure that required professional help, and the professional who helped us strongly disagreed with how we've been managing our SWG and pool chemistry following TFP's Pool Math instructions. I'd be grateful for some guidance on which way to go from here. Three issues came up involving the SWG and balance between FC and CYA; I hope it's okay to post them all in the SWG forum, because I suspect they may be related:
(1) Run Time vs. Efficiency. For several years, we had been following advice we saw here about some studies showing the SWG can do better running at higher percentage efficiency for a shorter run time than lower efficiency for longer run times. We usually set our timer to run the pumps and SWG between 4-5 hours (shorter in colder weather) at 85-90% efficiency. Once we started doing that, our electric bill dropped $100 per month, and the water was usually in great condition. This professional said that such a high percentage would kill the SWG, and he reset it to run for 10 hours a day at 40%. He also said that electricity was cheaper than the chemicals I would otherwise burn through--although that has not been our experience. Is there a right answer to this question? Can it be done either way, or are we really killing the SWG by running it at 85-90%?
(2) TFP Pool Math vs. SWG guidance on FC-CYA levels. The professional was also shocked that I was aiming for a free chlorine level of around 8, with levels occasionally going as high as 10 (during cold months when we're not in the pool). He said that the FC level should be between 2-3, and pointed to instructions on the inside cover of our SWG display, which did suggest levels closer to 2-3. He said that keeping the FC level so high would bleach out our vinyl liner, and would make the water bad for swimmers. My husband, who kept the water clear and pleasant for years, said that we'd have an instant algae bloom at a level of 2-3. I pointed to the Pool Math recommended guidelines showing much higher recommended levels, but the professional he said these numbers couldn't be right, and that commercial pools are legally required to close if the FC level gets to 10. Again, I'd be very grateful for advice about where to aim, and why there seems to be a difference between the guidance on our SWG display and the pool math on TFP.
He was also shocked that I was aiming for CYA levels between 50-60 and said it should be more like 100, which is way higher than TFP recommends, and even higher than our SWG display recommends. He said that the higher the CYA is, the lower percentage of time the SWG can run, and the longer it will last. He also said that every time I add a bag of salt, I should add a pound of stabilizer. I learned about the relationship between FC and CYA on your website, but my husband always took the opposite approach to the balance: keeping FC high and being conservative about adding too much CYA because it's so hard to reduce it if you overcorrect. I'd be grateful for advice about which way to go here.
(3) Cleaning the SWG with a Vinyl Pool. Finally, my husband used to clean the SWG at least once or twice a year, even though we have a vinyl pool. The professional told me that I never need to clean the SWG at all, and that he never does. He said that it was unnecessary with a vinyl pool, but needed with a cement pool. Is he right? I'd love to not have to do that if I don't really have to. Maybe it depends on the percentage efficiency you're running it at?
I'd be very grateful for any and all advice on how to reconcile this man's advice with what had been working for us for the last few years! --Erin
(1) Run Time vs. Efficiency. For several years, we had been following advice we saw here about some studies showing the SWG can do better running at higher percentage efficiency for a shorter run time than lower efficiency for longer run times. We usually set our timer to run the pumps and SWG between 4-5 hours (shorter in colder weather) at 85-90% efficiency. Once we started doing that, our electric bill dropped $100 per month, and the water was usually in great condition. This professional said that such a high percentage would kill the SWG, and he reset it to run for 10 hours a day at 40%. He also said that electricity was cheaper than the chemicals I would otherwise burn through--although that has not been our experience. Is there a right answer to this question? Can it be done either way, or are we really killing the SWG by running it at 85-90%?
(2) TFP Pool Math vs. SWG guidance on FC-CYA levels. The professional was also shocked that I was aiming for a free chlorine level of around 8, with levels occasionally going as high as 10 (during cold months when we're not in the pool). He said that the FC level should be between 2-3, and pointed to instructions on the inside cover of our SWG display, which did suggest levels closer to 2-3. He said that keeping the FC level so high would bleach out our vinyl liner, and would make the water bad for swimmers. My husband, who kept the water clear and pleasant for years, said that we'd have an instant algae bloom at a level of 2-3. I pointed to the Pool Math recommended guidelines showing much higher recommended levels, but the professional he said these numbers couldn't be right, and that commercial pools are legally required to close if the FC level gets to 10. Again, I'd be very grateful for advice about where to aim, and why there seems to be a difference between the guidance on our SWG display and the pool math on TFP.
He was also shocked that I was aiming for CYA levels between 50-60 and said it should be more like 100, which is way higher than TFP recommends, and even higher than our SWG display recommends. He said that the higher the CYA is, the lower percentage of time the SWG can run, and the longer it will last. He also said that every time I add a bag of salt, I should add a pound of stabilizer. I learned about the relationship between FC and CYA on your website, but my husband always took the opposite approach to the balance: keeping FC high and being conservative about adding too much CYA because it's so hard to reduce it if you overcorrect. I'd be grateful for advice about which way to go here.
(3) Cleaning the SWG with a Vinyl Pool. Finally, my husband used to clean the SWG at least once or twice a year, even though we have a vinyl pool. The professional told me that I never need to clean the SWG at all, and that he never does. He said that it was unnecessary with a vinyl pool, but needed with a cement pool. Is he right? I'd love to not have to do that if I don't really have to. Maybe it depends on the percentage efficiency you're running it at?
I'd be very grateful for any and all advice on how to reconcile this man's advice with what had been working for us for the last few years! --Erin
