Pure water?

[Loopy]

My tutor said using pure water was best to rehydrate PMC etc as it has no minerals in it, but I can't find any. She said chemists usually stock it but they just look at me blankly! And if I do a google search all I get is 'pure rose water' 'pure lavinder water'

Is pure water really needed?

Thanks

[Di Sandland]

distilled water - from Boots