pH concerns

I just had my water analyzed by ward labs. For my next IPA (West Coast style IPA) I'm adjusting the profile slightly with gypsum, baking soda and epsom salt to get it closer to San Diego water. According to Palmers nomograph, my tap water should put a 100% base malt mash at a pH of 5.32. After tweaking the water profile to match San Diego water, the pH goes to 5.28. The IPA recipe will be 2-row with 8% crystal malt and 8% carapils. I already get 85% efficiency on similar grain bills so I'm assuming I don't have pH problems. My problem is I'm color blind and can't read the pH strips very easily. I have some 5.2 buffer but researched it today and found multiple sources that claim it can add an off-flavor, I've never used it before. Should I relax and trust the nomograph?

Here's what I'm doing

My tap:
Ca = 27 ppm
MG = 10 ppm
Na = 30 ppm
Sulfate = 7 ppm
Cl = 87 ppm
Bicarbonate = 44 ppm
Residual Alkalinity as CaCO3 = 11 ppm (according to Palmer's spreadsheet)

After additions (10gm gypsum + 4gm Baking soda + 4gm Epsom salt into HLT with 11.7 gallons tap water):
Ca = 80 ppm
MG = 19 ppm
Na = 55 ppm
Sulfate = 169 ppm
Cl = 87 ppm
Bicarbonate = 109 ppm
Residual Alkalinity as CaCO3 = 23 ppm (according to Palmer's spreadsheet)

dstar26t said:

Should I relax and trust the nomograph?

Click to expand...

IMHO, yes. 5.2 is made for, AFAICT, homebrewers who don't bother to read water analyses, plot nomographs, and adjust their liquor.

and also for those who do and say "screw it all - I'm just adding some pH buffer!"

I use 5.2 in just about every beer I've brewed. There's no off flavor.

How can you have 109 ppm of carbonate, but only 23 ppm of calcium carbonate. Does not compute.

That's residual alkalinity. You need to read this. How to Brew - By John Palmer - Residual Alkalinity and Mash pH

Lil' Sparky said:

That's residual alkalinity. You need to read this. How to Brew - By John Palmer - Residual Alkalinity and Mash pH

Click to expand...

This has been incredibly helpful, thanks Sparky!