^^^^^ +1
If alk is low than ph will be low also. Dont worry about ph. You should be more concerned with the big 3, alk, cal, and mag. Also I would ditch the api kit and get salifert and or redsea kits. The api kits aren't very accurate IMHO. Also with a new tank the rock is going to be sucking up the big three for a while so you will notice them dropping on a regular basis by a large amount. At least my tank did. Also if your running gfo, it absorbs alk as well as phosphates.
HTH