Using RO water with no additives

Should I get something with a built in pH meter or should I buy an individual pH meter? I'd like something reliable and accurate. I was thinking around $65-80.

 

Some like this one.
http://www.thermoworks.com/High-Accuracy-pH-Meter-8689
You need calibration, cleaning, and storage solutions also.

I don't know of any TDS pH combinations, so I can't recommend one.

 

I am under the impression that the TDS meters only indicate that some solids are present, and not what those solids are. So this could only be used to tell you if you have hard-ish water, or soft water and nothing else. Am I correct?

 

That's right. But it's not just that there are "some" solids. They do tell you the amount. (But not the types.)

 

It only tells you the total Disolved ion content in ppm. It could be hardness (Ca and Mg), alkalinity (HCO3), flavor ions (Na, Cl, SO4), and most likely some combination of all the above. You could disolve table salt in distilled water and have a high TDS, and the water would not be hard.

For a water supply the TDS is an indicator of something changeing in the supply.

 

I guess I'll have to find a pH meter that will allow for higher temperature.

 

You should measure mash pH after cooling. You cannot predict reliably what the change in pH will be due to temperature because the super variable nature of the buffers, acids, and bases in the wort

 

You shouldn't measure mash pH at mash temps. It will destroy the electrode. Maybe there's a design out there somewhere that will last a long time at high temps, but I'm not aware of one.

 

The pH probes will fail fast at higher temps. The quoted range for the mash 5.2-5.6 is at room temperature measurements.

 

Ok, I was wondering why one would want such a thing then, other than to quality check RO water.

 

You can use it to get some assurance that your already known water profile probably hasn't changed since it was analyzed.

 

"probably" It's a cheap way to be fairly sure.