first measured mash pH

After studying up on Brunwater I finally brewed my first IPA with RO water and added salt additions to the mash and sparge water to hit an estimated 5.3 room temp mash pH.

After properly calibrating my milwaukee ph meter and cooling to room temps (about 69F), I measured the mash pH at 5.35 after about 15 minutes in the mash.  There was a bit of grain (very small amount) suspended in the sample I took.  I assumed this was a win?  Am I correct in thinking that or should I be working to adjust that reading even more if it happens next time with an acid addition?

I think it was close enough - but some here dial it in within a closer margin.  I doubt you will have any problems.  I use Brunwater and rarely even check pH anymore, because it seems so reliable for the styles I brew.

For me, that’s plenty close enough.

The difference between 5.3 and 5.35 is negligible particularly given the accuracy of pH meters.  What you have proven to yourself is that your RO water acts like real RO water.

Yep, same here.

Cool.  Thanks for the replies.  I figured that a .05 margin of error could be due to a variety of things (i.e. measured water amounts, pH meter calibration, temperature calibration used, my CaCl2 absorbing some extra water, etc).