Need to Raise CYA

[jccams]

Have been using the BBB method for two years and it has been great, CYA was about 100 when I started BBB and this year I filled the whole tube and the dot is still there so it is less than 20. I have a chlorine pac left from two years ago I would love to get rid of, it is trichlor about 5 1/2 pounds in the pac. Seems like the perfect opportunity, what do you think? How much of it would I need to consume to get from say 10 to about 40 or 50 if I go this route?

FC=4
CC=0
TA=70
PH=7.5
CYA<20

 

[JasonLion]

It would take about 175 oz of trichlor, or about 11 lbs, to raise CYA by 30. Raising CYA with trichlor is a very slow process.

 

[PSW]

Have been using the BBB method for two years and it has been great, CYA was about 100 when I started BBB and this year I filled the whole tube and the dot is still there so it is less than 20. I have a chlorine pac left from two years ago I would love to get rid of, it is trichlor about 5 1/2 pounds in the pac. Seems like the perfect opportunity, what do you think? How much of it would I need to consume to get from say 10 to about 40 or 50 if I go this route?

FC=4
CC=0
TA=70
PH=7.5
CYA<20

According to the pool calculator (effects of adding chemical section at bottom), adding 88oz of trichlor will raise your FC by 25, raise CYA by 15, lower pH by 1.35, and raise saly by 21.

So..a couple thoughts...
You would not want to do this all at once (to keep FC and pH in check).
Why are you shooting for 40-50 CYA? The appropriate rage is 30-50...and I would recommend at least STARTING at the lower end of that. You can always add more CYA..but lowering that number is much more difficult.

 

[jblizzle]

How does your pool look?

Seems like when all the CYA disappears over the winter there is sometime ammonia in the pool, although given that you are showing a FC reading, this may not be the case.

 

[jccams]

How does your pool look?

Seems like when all the CYA disappears over the winter there is sometime ammonia in the pool, although given that you are showing a FC reading, this may not be the case.

Pool looks great, opened clear and still had FC of about 1. CYA didn't disappear over the winter it has been a two year process of draining some periodically and then two closings where they drain below the returns. I'm in MI so it gets closed in the winter. My thought is even if it is a slow process I could consume what I have and keep the FC level at 4 or 5 and in about 3-4 weeks go back to bleach and add more stabilizer via the sock if needed. It seems like this will be my only opportunity to get rid of this stuff that I paid 45 bucks for without harming my water chemistry.

 

[jblizzle]

Or you can save it to use if you might go on vacation for a week or so.