If you want to use just plain tap water all thru the grow without ever having to worry about ph, you'll need to mix your own Super Soil, supply it a source of microbes, and allow it to "cook" undisturbed for 30-45 days so the microbes can multiply and flourish. When this is properly done, the microbes control ph, so you don't have to.
This is the way I've been growing for a long time now, and all my grows finish fine with nothing but tap water, no ph adjustments, and no additives during flowering.
There are several good Super Soil recipes out there.
I've also used a soilless medium (Pro-Mix HP) + dolomite lime + perlite, and Dyna-Gro nutes with good results. However, I had to adjust ph every time I fed my plants, and I hate adjusting ph.
