PH Management with cool water?

[arin]

So I don't know if this is a stupid question or not but I'm going to throw it out there because it will help me better manage my pool. I manage my chemical throughout the winter months and the water dips to 50 degrees worst case as I have read here and on pool calculator my CSI is best at higher PH (8.0). My CH is 400 not crazy out of suggested range but if I lower my PH to suggested 7.6 in cool water the CSI is close to out of range so I prefer to hold a high PH throughout the winter. My issue is the Taylor PH test kit only goes up to 8.0, could I run a higher PH like 8.2 or 8.4? Does the water balance at 8.0 if thats the case I wouldn't need to lower my PH with acid in the winter? Like I said it may be a stupid question but things get cloudy for me when concerned about CSI during cold water months. Thank you in advance for any clarification!

 

[JasonLion]

When the water is at or below 50 degrees you want the PH to be roughly 0.3 higher than your would otherwise keep it. However, you also want the PH below 8.2 or there is no way to measure what it actually is. Normally that should work out, since a typical PH is 7.8, and 0.3 higher is 8.1, which is lower than 8.2.

 

[arin]

Is there a way to test above 8.0, my Taylor test kit only reads to 8.0.

 

[Patrick_B]

Not with common pool test kits because it's higher than you want to be. Just shoot for pH under 7.8 and make easy. It's not going to damage your pool. Not even close to it.

 

[aussieta]

i stop testing ph during winter and then have to make a few adjustments when the water warms up again
my ch is only 260 (and thats adding a lot of ch to my tap water)
so to keep csi in range i run 7.8-7.9 ph in summer and let it go high in winter

 

[JasonLion]

Is there a way to test above 8.0, my Taylor test kit only reads to 8.0.

You have to learn the colors, which you can experiment with using the base demand test. The color for 8.2 is different from the color for 8.0, you just don't have a color reference for it.

 

[Malcolm]

Or similarly, I assume it would be possible to come up with a table that, based on the number of acid demand drops it takes to bring the pH down to 7.8, you would know the original pH. Has anyone figured that out?

 

[JasonLion]

Malcolm, If you know the TA and Borate levels you could in principal do a rough approximation that way, but there wouldn't be much precision.

 

[Malcolm]

Ah, yes, I forgot about those buffers. I do know those levels, so I might play around with that. In the winter, I'm happy with pH sitting near 8.0, but I don't want it to go significantly above that.

 

[arin]

I would like to learn the color for 8.2, can you explain base demand test more please?

 

[JasonLion]

The base demand test is designed to let you figure out how much chemical you need to raise the PH by your goal amount. It works by adding drops of a chemical to the PH test vial and counting drops. We don't care about the counting drops portion here. Instead you simply use the base demand reagent to change the PH of the sample while doing the PH test and watch how the color changes. Each drop of base demand reagent will raise the PH a bit (we don't know exactly how much as that varies with TA and other things). Since the PH test maxes out at a PH of 8.2, the final color, where an additional drop of base demand reagent doesn't change the color any further, is the PH of 8.2 color.

You might also want to read the Taylor instructions for the base demand test. It covers some details I don't mention here.

 

[arin]

Thank You for pointing me in the right direction once again!