If you have real soft limp hair that you can't seem to rinse shampoo or product out of, it's probably soft water.
If your hair is real dry and you can actually clarify that residue off and your shampoo or whatever cleanser rinses out well and you need more product than usual it's probably hard water.

I get buildup easy from the soft water. It seems like on CG nothing rinses out of my hair well.
Low porosity, medium texture.

If it smells good put it in your hair, if it tastes good spit it out!