water for formula... is it really that serious?

So we just started using the powered newborn formula and I realized we forgot to buy nursery water. As I was googling if it is okay to use purified bottled water, there were so many different answers! It seems like mostly they tell you to use nursery water without the flouride but everyone sells the one WITH flouride added. And some people just say whatever water you drink it fine, other say it contains floruide or sodium or chlorine etc.... what the heck, I'm a second time mom and I don't remember this being an issue last time.