I had asked this question some time ago, Arif. I thank you for those numbers. from what you post, it looks like 5.5 is a norm and that is acidic as compared to the "neutral" of 7. I know my city water is alkaline (up to 8) but have seen an article where adding water soluble fertilizer actually can bring it into a more normal range. I also am aware you can add small amounts of vinegar to bring it to proper range. As to the amounts, I would have to look it up but haven't. There are those paper dip sticks you can use to test your water's PH (such as used for fish tanks). Interesting discussion, thanks.