I use lactic acid to lower the pH when I'm doing very light beers. I assume you weren't talking about increasing acidity at this point.
I mean to lower the Ph, which I equated with adding acidity through some means. I was also just reading another thread on batch sparging, which may have impacted this beer, as well. I use about a 1.25 quarts of water per pound mash ratio, then after mashing (90 minutes), I add sparge water at 170 or so to get it to one-half of the total water, then drain, then add the other half of the total water at 170 or so and drain. I was under the impression that getting the water total to roughly half before the first draining was important when batch sparging. Could that be part of the problem?