Just thought I'd let you know about something I do. I don't have hard water, but when we prepare for Hurricane season, I majorly stock up on extra water to cleanse my hair in should the need arise. You could try buying some spring water or distilled water to shampoo your hair in. With your current length, it wouldn't take a whole lot of water, maybe 3 or 4 gallons. If you decide to try this, the first time you do it, you may want to use a clarifying shampoo or a shampoo product that will remove the mineral deposits on your hair. Just a suggestion.
I've seen your other pics, and your hair is beautiful. Keep it growin'!
Leona