My free, easily accessible, city supplied tap water is RO treated. 95% of everything is removed. The result is <1ppm of everything except chloride and sodium which are both at 20ppm. I think the ph is between 8 and 8.5. I plan on adding about 5 grams gypsum, 2 grams baking soda, and 1 gram epsom salt just to get some mineral content in there based on about 6 gallons strike water. I am batch sparging and am brewing an IPA with 12.5 # 2 row, 1#crystal 10, 1#rye, .5# victory and .5#carapils. I don't have anything to test ph at the moment but will at least go buy some ph test papers or colorphast plastic strips if available. Do you think my initial mash ph will be okay and should I be more concerned about the sparge ph? Or concerned about both? I read something from Ken Schwartz where he suggests adding 1 tablespoon of extract per gallon of water to the sparge water and even the strike water to make sure the ph is in an acceptable range of below 6. Have you heard of this or know anything about it?