Wade is correct, no further corrections are needed as the manufacturer has taken care of these issues for you. Even if your water at home has a weird pH (I always thought water was 7.0 but i guess not) you won't add enough of it to a kit to make a difference. If you are concerned you can always use bottled spring water to hydrate the kit.
Now I will add, if you are interested in bulk aging your wines it is nice to get a pH and sulfite's test kit to assure your sulfite levels are maintained during the bulk aging process. You really need both as to get a proper sulfite level you need to know the pH.
George sells some Accu-Vin kits that are very nice. I actually prefer these to using my pH meter. These tests are not required for kit making though and actually would have little use unless as I have said, you are bulk aging for an extended period of time.