how much apple juice for priming?

[johnnyt471]

I have 4 gallons of apple juice fermenting right now. I'm going to prime with more apple juice, and I wanted to know how much to use. The label on the juice I'm using says it has 26 g sugar per 8 fl oz.

 

[upnoath]

http://www.tastybrew.com/calculators/priming.html

The above link agrees with this scale:

http://www.howtobrew.com/section1/chapter11-4.html

And 1 ounce = 28.3495231 grams

 

[johnnyt471]

OK, so I used the calculator for
Cider - Standard Cider and Perry
volume of CO2 - 2.25
4 gallons
68 degrees

it says I should use 3 oz of glucose or 2.8 oz of sucrose.

Maybe I'm just an idiot...but what kind of sugar is in my organic apple juice from whole foods? and I noticed that the recipe I'm getting this from (http://www.savvyhousekeeping.com/how-to-make-apple-cider/) says that they use 4 oz sugar. would 4 oz be too much?