Ph a little low but.......

[ethany]

Last year I had stains and did the A Acid treatment and worked pretty well. I use hth metal control ( little cheaper than Mikes magic) and seems to work. My question is I just finished shocking the pool and there are not any stains which is great! But my ph is a little low at 7.0, can I leave it there without any issues?

I kept it at 7.2-7.4 last year and battled stains all year. Hoping a lower ph might help

 

[cowboycasey]

7.0 is on the low acidic side, where is your CSI level at in poolmath?

 

[pooldv]

That is good that you were able to shock with no stains. 7.0 is the lowest it should ever be. And is risky with a heater. 7.2 would make us all feel better about it.

 

[ethany]

Ok thanks.......do you think if I aerate it will bring it up enough?

And what is CSI?

 

[RobbieH]

Ok thanks.......do you think if I aerate it will bring it up enough?

And what is CSI?

Look at Pool Math.

http://www.troublefreepool.com/calc.html

 

[Richard320]

Ok thanks.......do you think if I aerate it will bring it up enough?

And what is CSI?

If the TA is relatively high, say 80 or better, then aeration should help. The higher the TA, the faster aeration raises pH.

CSI is a calculation that tells you whether your water is corrosive to plaster or if it's likely to start forming Calcium scale. Scale starts as some rough blotches and can progress into homegrown sandpaper that will rub the skin right off any body parts that brush against it. Keep CSI below .3 and you'll be okay. Most people never have to worry about it.

If you post full test results, we can quickly give you a yes or no answer and avoid a lot of ifs.

 

[pooldv]

More here, Pool School - Calcium Scaling
And here, Langelier and Calcite Saturation Indices (LSI and CSI)

 

[ethany]

Oh CH.......it's 250
Fc-2.5
Ph-7.0
TA-80
Cya-20 but yesterday put enough in to increase to 70

 

[Richard320]

Oh CH.......it's 250
Fc-2.5
Ph-7.0
TA-80
Cya-20 but yesterday put enough in to increase to 70

pH should be higher, then. At

FC 2.5
pH 7.2
TA 80
CH 250
CYA 70
Salt I'm guessing 3000 since you have a SWG
Temperature 80

CSI is -.7. That's too low for plaster, and might be bad for the gelcoat on your fiberglass pool.

Raising pH to 7.5 brings it to -.43 which is okay. You want to keep the pH up with a SWG anyway. See Pool School - Water Balance for SWGs

 

[ethany]

Thanks all.......my salt is a little high at 3300. I think I'm gonna do borates to keep things stable