I live in a country where the water is extremely"hard" and noticed that when I bought products from different countries, they didn't have the same effect.- I was wondering if hair-care companies adjust their ingredients to each market? what would the best product be for the scale from soft to hard? I guess it's like coffee and tea in different countries(they do taste differently even if I buy the product from the source).Anyone?
You could try an off the shelf filtered shower head. I got one once, made by "sprite" I think (not like the beverage). Just connects to your shower arm like any other shower head, but has a charcoal filter you can change. I would think shampoo is where you'd notice the issue the most. Years ago, KMS California used to make a conditioner that had EDTA in it, for use after swimming in chlorine (I used to use it in the early 80's, it was great, but all of KMS's product lines have been changed, alas). EDTA is a preservative, but also acts as a chelating agent and in theory it would remove some minerals in water? Yep, I think I remember some of my college chemistry because I just looked it up; see link. http://thebeautybrains.com/2008/09/28/beauty-q-a-does-malibu-treatment-remove-hard-water-and-rust-stains-from-hair/
The reason the products are different is that beauty companies truly do change the formulas slightly to suit different tastes. For example regular old nivea cream is actually a thinner more absorbent texture in north america than it is in europe (most european women seek a cream that is very rich and emollient while north american women prefer lighter textures). That's a fact. Every company will readjust formulas slightly to each market in order to meet the average woman's expectations and preferences. This also applies to almost anything. There are a lot more bar soaps available in the states, whereas in europe there are a lot more cream cleansers. It's just a matter of the overall population's preferences.