Mash pH & Brewing light beers

Wanting to brew a kolsch, blond or cream. Been using lactic acid to adjust mash pH. Wondering if salts would benefit pH lowering prior to adding any lactic. Or should I dilute with distilled or spring water, or boil out some of the temp hardness? Any advice will be appreciated since I do not fully understand water chemistry. I have noticed some astringency in some of my pales and IPAs which seems to dissipate with time and cold conditioning.

Local Water report-first num is typical concentration/second is range * These parameters will more likely be at the high end of the range during
high demand periods in the summer months of June, July and August.

Calcium CaCO3 50 40-60
Magnesium CaCO3 40 30-40
Total Hardness* CaCO3 90 85-100
Carbonate (CO3) CaCO3 20 15-30
Bicarbonate (HCO3) CaCO3 15 10-25
Total alkalinity CaCO3 35 25-60
Sodium* Na 44 30-60
Iron* Fe 0.2 0.1-0.5
Sulfate* SO4 70 40-150
Chloride* Cl 46 10-100
Silica* SiO2 10 9-14
Fluoride F 1.2 0.6-1.4
Phosphate, Tot P 0.8 0.2-1.0
Phosphate, Ortho P 0.2 0.1-0.5
Chloramine Cl2 (at plant tap) 2.0 1.0-3.5
pH pH units 9.4 9.2-9.8
Turbidity NTU 0.2 NTU 0.1-0.5
Conductivity* uS/cm 350 250-750

Looks to me your water is super soft. That's good for lighter beers like you describe, afaic. Your pH is SUPER high, though. "Normal" water is around 7-8.

I'd first bring your pH down by diluting with water, then use pH5.2 stabilizer to bring the pH down without adding any extra salts.

My 2cents.

and now for my 2 cents. use CaCl2 to bring your mash pH down. I really like this sheet from palmer's sight.
http://www.howtobrew.com/images/f83.pdf
I have read nothing but good things about having Ca in your mash, boil, and ferment. read palmers sight and use CaCl2 to adjust your pH. If your Chloride level starts to get to high replace some of the CaCl2 with CaSO4.

Starting with soft water and relatively lower amounts of all the important ions, you're sitting in pretty good shape in that you can add pretty much whichever salts you want to match whichever water profile you want (or at least with little dilution).

The MOST IMPORTANT part is getting the mash pH down around 5.2-5.4. Adding enough lactic acid to achieve that might give your brew a sour taste, though, since you're starting around 9 with your base water. So, like squiggy said, you can bring it down with CaCl2 or gypsum, if you don't mind the ion contents changing.

I use this often (in conjuction with brewater 3.0):
http://howtobrew.com/section3/Palmers_Mash_RA_ver2b.xls for standard

http://howtobrew.com/section3/Palmer...c_RA_ver2b.xls for metric

+1 on CaCl2 or gypsum

Thanks everyone for the input, I think I'll end up diluting(1pt tap:2pt dist) and then adding some gypsum(what I have on hand) for my upcoming kolsch using the palmer spreadsheet to calculate amounts. I'm sure I'll pick up some calcium chloride when I'm at Things Beer for the cream, blonde or wheat coming up next. I'm trying out the WLP080 Cream Ale Blend on a few similar styles.