Baking soda will work well for PH up. I don't know of any common household items for PH down (there probably are some though). Don't let anyone tell you that vinegar will work because it won't(not for me at least). Sulfuric Acid(for ph down) is sold as swimming pool acid and it is REAL cheap. I bought 2 gallons at a grocery store for approx 4 dollars and that is enough to go through a few grows at least. I adjust my water ph levels, don't know how the soils can be adjusted ... also be sure to buy a measuring kit and I would recommend the readily available ph down or ph up formulas available at any hydro store or pet/fish store, theyre not too expensive and save you lots of trouble.
