Ascorbic versus Oxalic Acid / CYA pre-dilution

[smallpooldad]

Thank you for your reply.

The pool is much better although there are some stains reappearing. The pool water was 7.8 when I refilled it and I am now maintaining it at 7.5, which seems to just stay there as long as the alkalinity is maintained at 100 not allowing for the CYA adjustment. The CYA is now 33 is this too high?

The cl is between 4 and 6 is this too high?

I did add metal out and a polyquat when I refilled.

Next time I'll try holding it 7.2 for two weeks and putting pucks in the skimmer

[mbar]

Your cya is good. Your chlorine level is fine - you can keep it closer to 4 - here is the best guess chart:


Stabilizer . . . . . . Min. FC . . . . Max FC . . . 'Shock' FC
=> 0 ppm . . . . . . . 1 ppm . . . . . 3 ppm . . . . 10 ppm
=> 10 - 20 ppm . . . . 2 ppm . . . . . 5 ppm . . . . 12 ppm
=> 30 - 50 ppm . . . . 3 ppm . . . . . 6 ppm . . . . 15 ppm
=> 60 - 90 ppm . . . . 5 ppm . . . . . 10 ppm . . .. 20 ppm
=> 100 - 200 ppm . . . 8 ppm . . . . . 15 ppm . . .. 25 ppm

As you can see with a cya of around 30 you can keep it on the low side around 3-4. I would run my ph around 7.2 to 7.4. You may want to add some more metal out, if the stains are coming back you don't have the metal in the water staying in solution. - and run your pump 24/7 for a couple of more days. Don't shock the pool for at least 2 weeks, I only shock if I have combined chlorine. Remember the pucks will add cya, and also bring down your ph because they are acidic, so I would keep the puck in the skimmer for a couple of days, if you have either a DE or sand filter.

[duraleigh]

Hi, Paul,

I can't comment on the stain issue...wish I knew more.

Your CYA of 33 (is that a pool store reading?) and Cl of 4-6ppm are just fine. Your CYA will slowly rise if you continue using pucks. You might want to think about an alternate source of Cl.

Dave S.

[smallpooldad]

Once again thank you to both of you.

I will drop the ph to 7.2 and put a puck in the basket. I will also add more metal out and use liquid chlorine to adjust cl in the future.