First time owning a pool this year, and it's been very educational! Thank you TFP Pool School!
Short story:
Do I understand this chart correctly... if the CYA level is 90 or above for a non-SWG pool, it's safe to swim with FC at 10ppm?
pool-school/chlorine_cya_chart_shock
Long story:
Made the rookie mistake of using nothing but Trichlor tabs for the first 6 months. Over time, algae kept blooming and became harder to kill. After going to Pool School, I learned it was due to increasing CYA levels. I stopped using the tabs and switched to bleach. I elevated the FC > 10ppm for about week and finally got rid of the algae. Water is a nice clear blue now.
I have not added any chlorine since the last shock treatment on 8/16. The pool gets a lot of sun during the day and it has been very warm and sunny here in San Jose CA. I do have a clear solar blanket on the water (don't know if that affects FC). But I'm surprised the FC has remained high for so long. I confess that I did not have a good test kit during the shock treatment, so I suspect I went overboard with the bleach / Cal Hypo to eliminate the algae.
I just received my TF-100 XL kit today, but it was too dark for an accurate test. Instead I did a quick check with strips:
TC 10 (strip cant test above 10)
FC 10 (strip cant test above 10)
TA 80
PH 6.6
TH 500
My CYA is somewhere between 50 and 90 based on two tests from two local pool shops. I'll get my own reading tomorrow with the TF-100 kit.
So, if my CYA is near 90, is it safe to swim with FC at 10 (assuming I increase my PH to the proper levels)?
Short story:
Do I understand this chart correctly... if the CYA level is 90 or above for a non-SWG pool, it's safe to swim with FC at 10ppm?
pool-school/chlorine_cya_chart_shock
Long story:
Made the rookie mistake of using nothing but Trichlor tabs for the first 6 months. Over time, algae kept blooming and became harder to kill. After going to Pool School, I learned it was due to increasing CYA levels. I stopped using the tabs and switched to bleach. I elevated the FC > 10ppm for about week and finally got rid of the algae. Water is a nice clear blue now.
I have not added any chlorine since the last shock treatment on 8/16. The pool gets a lot of sun during the day and it has been very warm and sunny here in San Jose CA. I do have a clear solar blanket on the water (don't know if that affects FC). But I'm surprised the FC has remained high for so long. I confess that I did not have a good test kit during the shock treatment, so I suspect I went overboard with the bleach / Cal Hypo to eliminate the algae.
I just received my TF-100 XL kit today, but it was too dark for an accurate test. Instead I did a quick check with strips:
TC 10 (strip cant test above 10)
FC 10 (strip cant test above 10)
TA 80
PH 6.6
TH 500
My CYA is somewhere between 50 and 90 based on two tests from two local pool shops. I'll get my own reading tomorrow with the TF-100 kit.
So, if my CYA is near 90, is it safe to swim with FC at 10 (assuming I increase my PH to the proper levels)?
