First water is the highest degree of quality (or purity) in diamonds or pearls.
The expression can also be used to describe a pianist etc. being of the "first water" i.e. top quality.
By the way did you manage to get your horrid problem sorted out yesterday? I was extremely sorry to hear about it particularly as you are always so helpful to everybody
hi Redcoral
Yes, hopefully the email problem has been resolved and, as far as I know, all the posts that were not mine, have been removed.
Enjoy the rest of the weekend . J