Hard or basic?
GH and KH are more important that pH, if your water is coming out of the tap at 7.5 and you want it lower than that then you really need to know the hardness. If the hardness is low it may be as simple as adding a bit of driftwood and/or peat to your tank, but if the water has a high mineral content (if you're getting it from a spring/bore in a limestone area, for example) you may need to look at collecting rainwater or a Reverse Osmosis unit.