I use 8tbsp of limewater with 1/2 of a large lemon but of course I sometimes buy smaller lemons and have to reduce the amount of limewater. 1-2 tbs BSM, a pinch of espom salt and clean water to fill the rest of the glass with.
Of course I have been on it for a while. Everyone should start off with just 1-2 tablespoons of limewater until they feel their body is ready to try upping the amounts.