First I have to say thanks to Ben and all of you for your years of experience & help that make it easy to have a pool. I have used the forum info for several years and it is a blessing indeed – even with a pool with an ionizer. We had nothing but success & easy water for several years with the ionizer & this forum (until the unit died) & the info in this forum mostly applied across the board to the basic daily care. My other half plans on restoring the ionizer, but time is not on my side for summer swimming. As for the forum – IT LIVES!!!...and eveyone is glad!!!! Hopefully with time most of the ’lost’ info will be restored.

Now to my question:

It may already be here, but I haven't found it, yet....

When adding CYA, how much will it raise the CYA in a pool?? The container says 3 pounds per 12,000 gallons if your CYA is less than 40, but does not indicate how much of an increase to expect. I will be adding through the skimmer and giving it 2-3 days to see where it will level off, but I'd like to avoid overshooting. Current level is less than 30, but not totally gone.

Pool is 33’ x 54”, ~34000 gallons, AG, sand filter, round with ~25’ diameter centered bowl, depth of 6 feet @ center of bowl, in South Carolina.

Results this evening were:

Water Temp = currently averaging about 50F, give or take 5 or so depending on ambient temps
pH = 7.2 - holding steady...
FC = 7.5 – will have added 3#’s of CalHypo by the time you have read this to inc FC by ~6/7ppm
CC = 0.5
(TC = 8.0)
TA = 130
CYA = Confirmed at <30>0
CH = 70* due only to using CalHypo recently

It appears that I am losing ~4ppm in FC out of ~5ppm added over a 12 hr period.

Have been using bleach, but it kept dropping pH below 7.2, even adding Borax, so I switched over to CalHypo using the better way to add CalHypo for awhile, hoping to help ‘stabilize’ the pH & TA, and it has worked for the pH. I will be adding more Borax to push the pH up after the CYA has been added, and also watching the TA to keep it from rising too much. Back to bleach after that.

Water is now clear, liner looks mostly blue, as it should, but I do have a little green algae on the liner that is proving stubborn in some spots, so I had made an effort to keep the FC between 10-15, which was working until the CYA levels dropped below 30 and I was out of town for a couple of days - I’m the designated ‘Pool Guy’. The CYA levels came from using TriChlor late last year for a while. With the ionizer, I never needed to worry about the CYA levels.

Also, when I add the CYA, how long is a safe waiting period before adding anything else through the skimmer? I can always add bleach directly to the pool to boost the FC & to avoid unexpected surprises in the filter.

Thanks.