Simply put the water in Florence is terrible. It is hard and abrasive. When I told people this they often don’t believe me, but it seems that when it comes to water in Italy Florence drew the short straw.
My skin and hair were both dry and oily at the same time, there was a black residue that was always in the bottom of the shower that needed to be scrubbed off. The water tasted funny in cooking. So not only did we drink bottled water but we also used this water to make tea and often cook with too.
My first piece of advice is that this is what the water is like, so you are going to have to adapt. It is likely that the wonderful shampoo and body wash that you have brought from home is not suited to this type of water. So the first thing you should do is buy some new stuff that is perhaps better for the conditions. Take a look at my post about where you can buy toiletries from in Florence as this is not necessarily straight forward.
I resorted to washing my hair only once a week – which was great as this is something that I have wanted to be able to do for years. It was so oily after washing that it was better if I just left it unwashed. And what do you know after a few weeks my hair was used to it and better for it.
On top of how difficult the water can be for your body you should see how stiff your clothes come out of the wash. I definitely had to run everything through the dryer after a wash otherwise my towel would scratch up my skin that was already suffering from the water.
Now it is not common to have a dryer in apartments in Florence so we had a weekly ritual of walking down to the laundromat with a bag of wet laundry to run through the dryer. It didn’t cost much as it is was partially dried already and already washed.
So the water is hard, there isn’t much you can do about it. But you can adapt and accept it as part of the reality of living in Florence.