I know this topic has been covered ad nauseam but I would like to relate the details of my CYA experience.
Background:
I have been at this pool chemistry game for five years. I'm certainly no expert but with the help of this forum, I have successfully managed my pool through five seasons with no surprises; that is, until last summer (2021)
Strategy:
Over the years I have found a chemical "sauce" that seems to work well. This recipe keeps the CSI well within the normal range.
CYA - 70 having crept up during the season
FC - 10 10% liquid sodium hypochlorite
PH - 8.0
TA - 50
CH - 500
Temp around 86
Note: For better or worse, I run a fairly high PH with a correspondingly low TA. With the opposite setup (TA 70-90 and lower PH 7.2-7.6) I found myself chasing my tail, adding more sodium bicarb for TA, more acid for PH, more 'bicarb, more acid, etc. . .
Scenario:
Last year mid-summer, with chemicals balanced quite nicely and the water having that certain polished look, I began to notice the CC slowly creeping up. With low bather load, the CC went to 1.6-1.8 despite my persistent use of liquid chlorine approaching shock levels. The pool smelled of chlorine and ammonia. After a period of two-three weeks and much chlorine, the numbers slowly returned to normal. I then tested all chemicals and found the CYA to have fallen from 70 to barely 20. I ran the CYA test again with the same result. I refused to believe the test.
With chlorine levels safe for 70 CYA but dangerously high for 20 CYA, I went swimming and suffered foggy vision for nearly two days. I closed the pool until the excess chlorine burned off and resorted to Tri-Chlor to increase CYA for the remainder of the season.
The pool was surrounded by bare, unlandscaped ground with a recent addition of compost. High summer winds prevailed during this period, with some soil found in the pool.
Opening the pool 2022:
March - April :
CYA <30. Added Tri-Chlor that brought CYA to 45
May:
More windstorms, more soil in the pool.
CYA tested, dropping from 45 to 30ppm. Once again, I have now resorted to tabs until the CYA is within the normal range. (I know I could buy stabilizer, but artificially raising CYA just goes against my grain.)
Question: Could soil that contaminates the pool cause CYA to disappear so rapidly? CYA that disappeared not only last year but this year as well? I mostly understand that certain bacteria under the right conditions change the CYA, but a 40-point drop in CYA in 2-3 weeks is crazy in my mind.
All help is appreciated.
Bud
Sacramento, CA
Background:
I have been at this pool chemistry game for five years. I'm certainly no expert but with the help of this forum, I have successfully managed my pool through five seasons with no surprises; that is, until last summer (2021)
Strategy:
Over the years I have found a chemical "sauce" that seems to work well. This recipe keeps the CSI well within the normal range.
CYA - 70 having crept up during the season
FC - 10 10% liquid sodium hypochlorite
PH - 8.0
TA - 50
CH - 500
Temp around 86
Note: For better or worse, I run a fairly high PH with a correspondingly low TA. With the opposite setup (TA 70-90 and lower PH 7.2-7.6) I found myself chasing my tail, adding more sodium bicarb for TA, more acid for PH, more 'bicarb, more acid, etc. . .
Scenario:
Last year mid-summer, with chemicals balanced quite nicely and the water having that certain polished look, I began to notice the CC slowly creeping up. With low bather load, the CC went to 1.6-1.8 despite my persistent use of liquid chlorine approaching shock levels. The pool smelled of chlorine and ammonia. After a period of two-three weeks and much chlorine, the numbers slowly returned to normal. I then tested all chemicals and found the CYA to have fallen from 70 to barely 20. I ran the CYA test again with the same result. I refused to believe the test.
With chlorine levels safe for 70 CYA but dangerously high for 20 CYA, I went swimming and suffered foggy vision for nearly two days. I closed the pool until the excess chlorine burned off and resorted to Tri-Chlor to increase CYA for the remainder of the season.
The pool was surrounded by bare, unlandscaped ground with a recent addition of compost. High summer winds prevailed during this period, with some soil found in the pool.
Opening the pool 2022:
March - April :
CYA <30. Added Tri-Chlor that brought CYA to 45
May:
More windstorms, more soil in the pool.
CYA tested, dropping from 45 to 30ppm. Once again, I have now resorted to tabs until the CYA is within the normal range. (I know I could buy stabilizer, but artificially raising CYA just goes against my grain.)
Question: Could soil that contaminates the pool cause CYA to disappear so rapidly? CYA that disappeared not only last year but this year as well? I mostly understand that certain bacteria under the right conditions change the CYA, but a 40-point drop in CYA in 2-3 weeks is crazy in my mind.
All help is appreciated.
Bud
Sacramento, CA
