[somewhatshocked]

I wouldn't worry about your pH during the initial 'cycle' process as it is likely to be all over the place. You'll want to wait until your cycle is finished and then see what your water parameters settle at.

What's your KH? GH?

Using chemicals to alter pH isn't something I would advise. Erpetoichthys calabaricus do well in just about any pH, if that's the species you'll be keeping. Your tap water will likely be just fine.

Most species you can keep in an aquarium will do fine with tap.