Brewing an ocktober. 5lbs pils, 4lbs Munich, 3lbs Vienna, 1lb caramunich. My tap water has a pH of 7.4. using bru'n water it tells my to add 5ml of lactic acid to my 5 gallons of strike water to achieve a mash pH of 5.4. using pH test strips a very pale color shows indicating a very low mash...