Hi Kay,
Regarding how much sugar to use in the rock candy recipe, that recipe doesn't give a specific amount. You would keep adding sugar until, as the recipe states, you've added all the sugar that the water will absorb. If you'd like to work with a recipe that has exact measurements here are a couple of recipes previously shared:
Rock Candy Board: Daily Recipe Swap at Recipelink.com
From: Kelly~WA
Rock CandyBoard: Cooking Club at Recipelink.com
From: Nancy B 10-30-1998
Happy Cooking!
Betsy at Recipelink.com
In response to:
How much sugar?
Kay