How much water to add to scotch?

I sent this message to the Scotchcast lads in April 2012.

I decided to start drinking 3 years ago at Lark Music Camp after sharing scotch and chocolate during a morning class (singing highland pipe tunes acappella). Thanks for showing me the way.

How much water do you guys add to what amount of scotch?
jaya
_________________

My letter was answered in the May 2012 podcast, The Scotchcast 5th Anniversary show.