HIGH ph SALT POOL/ Help lower

[Ed Armstrong]

Hi Folks,

Opened last week, 4 yr old, 22000 salt water with vinyl liner, cartridge filter, got running and attempted to balance;

Taylor test kit reflects-
Chlorine - 8
FC - 0
TA- 60-80
CYA - 80
C.Hardness-- near zero
**PH- off chart to read, red with hint of purple, estimating 10-11**

Can you suggest what I might to to lower the PH into acceptable levels?? Last year ran steady high at about 7.8 all summer.

Thanks
Ed

 

[tjf]

Muriatic acid will do it. My local Home Depot carries it. See the pool calculator in my sig to determine how much to add. Do it in small doses so you don't overshoot your target.

 

[duraleigh]

Once you lower your pH as tjf suggests, you desperately need to get some chlorine in your pool.

read "The ABC's of Pool Water Chemistry" up in Pool School....an excellent place to start

 

[tjf]

duraleigh,

Why is his chlorine need 'desperate' ? (I'm asking, not challenging, as quotes tend to imply)

CYA chart shows Min FC as 6 for his CYA, and Target FC of 9 -- he's at 8. What am I missing?

Thx!

 

[JasonLion]

I image that duraleigh is reacting to the line which says "FC - 0". FC is free chlorine, which is the kind of chlorine you want to have in the pool. The previous line that says "Chlorine - 8" is ambiguous, and might refer to TC or CC, either of which would indicate a problem.

 

[tjf]

Ah, that's what I was overlooking. Duh. More coffee, please.

Thx, Jason.

 

[Ed Armstrong]

Hey guys, I'm sorry on that chlorine,

I thought the same thing initially from your response saying to myself I thought my chlorine reading was right on,

that chlorine reading was for the "good chlorine" the free chlorine, at a reading of 8

not Combined Chlorine

Thanks
Ed

 

[Ed Armstrong]

can you suggest what type of muriatic acid to buy from Home Depot? A particular strength or brand name? The calculator offers several choices and percentage strengths so I'm unsure of which to choose to do the calculations :? .

Thanks
Ed

 

[jblizzle]

The 31% is usually the better deal.

 

[chem geek]

It's up to you and usually comes in two strengths. The full-strength Muriatic Acid is 31.45% Hydrochloric Acid. It's less to carry and is usually priced more economically, but it fumes so you need to be up-wind of it when pouring. There is also usually a half-strength version that is 15-16% Hydrochloric Acid and it doesn't fume as much, but it's not always half the price so may not be as economical. I don't think the brand really matters.

 

[Ed Armstrong]

Hi Guys,

I added about 3/4 gal of muriatic acid, brought ph down (i think) overnight to a light tannish/yellowish. Now I'm thinking I'm a bit low since it was similar mostly to the 7.2 yellow on the test glass. I added a little PH+ (sodium carbonate), maybe about 24 oz, ph phenol test now shows a light reddish color. Question is, test indicator goes from tannish yellow to a light purple to dark purple. Is my medium red indicating a move towards high ph again? Initially, I had a dark red when I was told ph was high, that's why I posted to the forum and then based on that added some muriatic acid. At this point dont know whether to add a little more ph+ or a little acid?? I'm unsure where the reddish color is on the scale. Thanks again for all the advice!! Much appreciated.

 

[tjf]

Honestly, 7.2 is fine. It will drift up due to aeration, etc, over time.

Did you use Pool Calculator to determine the amounts to add?

 

[Ed Armstrong]

Well, it was 7.2 yesterday before I added the 1 1/2 lbs of PH+ sodium carbonate, now, as I said, it's a medium red??? I dont know if thats high again or low.

I had assumed (perhaps foolishly dare I say it) that red was high ph, about 2 above the deep purple high of 7.8 on the tester, estimated at about an 11 PH, which is what orginally two days ago prompted me to add the muriatic acid, which got it to a tannish yellowish, close to the 7.2 on the tester. But now, after trying to bring it up a bit with the PH+, its a medium red, (not yellow low PH or purple high PH). Unsure at this point???