Silver_Surfer said:Cross that bridge when you come to it, but lime and sulfur can be used to swing the PH up or down. Even baking soda can raise the PH.
Baking soda would kill the plants! Sodium is VERY Toxic to plants! It's like adding table salt!
Things that lower pH (More Acidic)
#1: Vinegar (1 Tbsp per gallon of water)
#2: Ammonium sulfate
#3: Sulfur coated Urea
Things that raise pH (More Alkaline)
#1: Lime
#2: Dolomite Lime (will only raise it so far)
#3: Ground Eggshells (really slow)
Good news is, most of that stuff is dirt cheap and easily available just about anywhere.