Water you use with powdered formula

Al

Ok.. a lactation consultant said to boil water first as there is something in the formula that comes from the container it’s in and the boiled water gets rid of it. Which is weird to me since its in a bag in the container.

I have read online some people use distilled water, nursery water, filtered water from fridge or just straight tap water if they are in an area with good tap water.

What do all you ladies use?