Okay, based on yesterday's thread, I'm shocking my pool right now. The odd thing is that, since the rain storm last week that kicked off this whole problem, my pH has slowly been raising. It stayed solid at 7.4 for weeks. Since the rain storm, it's gone to 7.8, and now looks close to 7.2.
I realized today (or at least it registered in my brain today) that my return was pointed up enough to be aerating. Would that cause the pH to raise?