Winter High PH vs Low CSI

[Cluckr7]

Looking for thoughts on if I need to keep PH below 8 as long as CSI is fine?

My water tests:
- TA 80
- CH 350
- CYA 60
- Salt: 3200
- Typical temp: 50-60 in winter
- No borates

At a PH of 8.0, the CSI is -0.06.
At a PH of 7.8, the CSI is -0.26.

My PH tends to gradually rise (3 month old plaster, high TA fill water, SWG).

How high can I let PH get above 8.0 as long as CSI is <0.3? How low should I go below a -0.3 CSI when I add acid?

Staying above -0.3 CSI and under 8.0 Ph is a pretty narrow band...lots of tiny, regular acid adds.

 

[mknauss]

As water temperature rises, your CSI will rise.
Right now, when your pH reaches 8, lower it to 7.8. When the water warms, you will be able to go down to 7.6

 

[Cluckr7]

So I could get calcium scale with a PH above 8 even with a CSI of say 0.1 or 0.2?

Besides scale, are there other risks of say 8.1-8.3 PH?

 

[mknauss]

So I could get calcium scale with a PH above 8 even with a CSI of say 0.1 or 0.2?

Not likely. But you cannot measure a pH greater than 8 or so.

There are no risks from a higher pH (within reason) other than scale.

 

[Cluckr7]

Ok great, thank you!

I probably won’t correct my Ph until it gets to 8.2 (0.2 CSI) and see how that goes. And then dose acid so PH goes down to 7.8 (-0.2 CSI). Crossing my fingers for no scale!