Another Water Quality Question

[johnnybob]

Here in Las Vegas we have very hard water, so I've always used R.O. water from the machine at the grocery store. The resulting beers have always been good. I tend to brew Pale Ales, IPAs, Cream Ales, and Wheat beers mostly. I always use 1 Tbls. of 5.2 Buffer in the mash. I was told that I shouldn't use pure R.O. water for all grain brewing. If I want to add some minerals how is it done and how much do I add? Do I make the mineral additions to the mash? Or could I simply substitute 1 or 2 gallons of tap water for some of the R.O.
Here are some of the numbers from my water report:

Calcium - 81 PPM
Magnesium - 28 PPM
Chlorine - 1.07 PPM
Potassium - 6 PPM
PH - 7.8
Hardness - 275 PPM or 16 grains per gallon (very hard)

If you need to see any thing else from the water report let me know.
Thanks for taking the time to help out. Any answers will be appreciated.

 

[RichBenn]

Have you read the sticky over in the Brew Science section?:
https://www.homebrewtalk.com/f128/brewing-water-profiles-tools-131443/
There is a great set of videos there that pretty much explain how to use a free spreadsheet to calculate ranges for different styles. I just did, but unfortunately my water report is incomplete, so I need to pay a lab for the right numbers.

Sounds like you could dilute your water and get close for those styles, but you need to plug the numbers into the spreadsheet to be certain. Only thing is you may want to pre-boil your water to rid it of the chlorine. No big deal, as you have to heat it anyway for mashing....

BTW, thanks to those that did the spreadsheet and video. Gotta love the helpful people in this place! Happy New Year!

Rich