pH in a four day old tank

day 1 - mixing salt, water, heat, running the tank
day 2 - added "live" sand (the arag alive stuff), live rock, base rock
day 3 - tested and moaned about pH being 7.7
day 4 - pulling hair out from pH being 7.7

it seems no matter what buffers I add, the pH is bound and determined to be under 8.0!!! Is it common to have such difficulty pulling up the pH in such a new tank? salinity is good, ammonia is just starting to take off... I can't find info on pH in new tanks being low!

my reef master test kit is supposed to arrive via ups tomorrow... till then, no, i don't know the kh.... i don't think i have low oxygenation, the filter agitation is really high and it has one of those venturi things that infuses air into the water... there was an O2 test i saw, i debated getting it, maybe i will if the kh is fine!!

I am using Reef Crystals

well, i tested it yesterday and today, and my kit seems to be confusing!! It is the aquarium pharmaceuticals carbonate hardness test. It says to add one drop and the tube should turn blue (it does). And then you continue to add drops, one a time, until the tube turns to pale yellow. It never does. It just gets darker and darker blue. The drop is yellow when it drops in, but when I shake it it turns to blue. Maybe someone with more experience testing KH can help me out a bit.

On the plus side, I've got brand new macro algae shoots (looks like anyway) on my live rock!