Quick read through and I think everyone missed the 3 most important things you need to know.
1) The cycle itself causes depressed ph.
2) Adding a half a bottle of, well, anything will nuke a tank. Fortunately it was buffer, which all just precipitated out with calcium. So now you have white crap all in the dirt/rock - and most likely low calcium and high alk. Do yourself a favor and 1) Read instructions 2) ignore LFS employees who contradict instructions.
3) pH is dependent on the o2/c02 content of water. You should take a glass of tank water outside and aerate it properly and see if the ph rises. If it does, lack of O2 in the water is your problem.
Wow Stop and take a breath! Exhale! Ok try to change the water to get rid of some of that white crud. Then try and direct the flow at the surface more to get more oxygenation to help the dissipation along.(as mentioned above) Also as mentioned most of these buffers are Calcium carbonate hence the higher Calc., also if I'm not mistaken baking soda acts in much the same way(sodium bicarbonate) Dont spend money on that stuff! You havent even given your tank a chance to get itself going.
Also as mentioned and I can't stress this enough BE PATIENT, Dont rush things along we've all been there and trying to save you the trial and error already experienced (right Brian) Read thru about 10 pages of these post maybe more and you will find plenty of people that have gone thru the same if not similar issues and 1 thing always rings true! Be patient!
KYLE^ Are you trying to apply for a job at Reef Culture nice Free advertisement! LOL:wavehand: