Subcool does use PH down in his water, he says he doesn't really worry about testing the PH all the time.
he actually uses non organic ph down and the reason he does for this is this, the water companies treat the water with the same sort of stuff that's in PH down so it doesn't really make a difference, which is true, so I started PH down in my water, never have any defs now. Anther so called organic way is using citric acid instead of lemon juice but ive read this can cause probs too.
after I heard subs reasoning for ph down, I thought he's right, the water companies put a lot more shit into the water to clean it than PH down. I reckon you'll plants would prefer properly PH'd water over PH 8 water anyday, however it got to the PH.
i will add though that i filter all my water and let it sit with airstones for atleast 48 hours.