Low Ph

[Maxemily]

The tub PH is rock solid at 7.3

TA 70

CH 200 (forgot to use soft water on last refill, duh!)

CYA 45

Pool Calc. -0.31

I can get the PH to 7.6 just after running the jets with full air, but overnight we're right back to 7.3.

I use Chemgeeks system except since I accidentally bought Dupont powdered chlorine (24%) from Lowes instead of MPS, I am using that instead of Clorox. Which, by the way, I now prefer.

Any thoughts on raising and maintaining the PH level? The pool calculator indicates a PH of 7.6 would get me to -0.03.

[chem geek]

If the Dupont powdered chlorine is a weak Dichlor, then this is net acidic and would also increase the CYA level. If it's Lithium Hypochlorite, then it should have the same effect as using bleach. Do you have a link to the Dupont chlorine product you are using? I didn't think Dupont makes chlorine -- only Oxone which is MPS and also chlorine dioxide. What does it say on the ingredients label of the Dupont product?

Richard

[Maxemily]

Thanks for the response Richard,

Unfortunately I transferred the product into a sealed pail so I do not have the packaging. It must be the Multifunctional Shock as this is all they sell.

I will test my CYA in a week, that will comfirm the product. I guess I could test for MPS, but that will have to wait since I just shocked with MPS. Which brings me to another question; how much Dupont 85% Oxone is correct for a weekly shock? I read MPS as a shock on many posts, but I don't see quantities.

Konrad

Update: My CYA is 70. This indicates your correctness. I just had the wife bring home Clorox. Do you feel this will correct my PH issue also?

[chem geek]

If you keep up with enough sanitizer/oxidizer during the week, then the weekly shock isn't technically necessary, but usually people shock up to around 10 ppm FC or about 5 teaspoons of Dichlor in 350 gallons or 10 teaspoons of non-chlorine shock (MPS). This would be on the high side.

Your pH tends to be low because the product you are using that appears to contain Dichlor is net acidic including chlorine usage. So yes, using bleach at this point should have your pH settle in at a higher pH. If you had continued to use Dichlor, you could have just raised the TA to have a higher pH, but since you are switching to bleach you can keep the pH where it is.