pH Theories

Hi,
I am new here and am wondering what you all know about different pH theories. I work with holistic health and have recently been studying about a variety of metaboloic imbalances. According to some, being too alkaline is as serious as being too acid. According to Carey Reams 6.4 is ideal for both urine and saliva - people that follow his methods work with a vatiety of calciums to push the pH in opposite directions to get it in that optimal zone. Also, those related to metabolic typing say that there are many other metabolic factors that can affect pH besides food and that each person will be affected differently. Any thoughts on that?
Ron Tweet