You should spend $10 for a digital gram scale. Measuring a granular substance like table sugar volumetrically introduces a significant margin of error depending on the size of the sugar crystals and how densely they are packed. That will give you greater control over carbonation levels.
And like others have said, you only get skunking with UV exposure.
The Fiesty(sic) Goat Brewery est. 2007 & Clusterfuggle Experimental Ales est. 2009
Primary: Saison, Berliner Weisse, sLambic I, sLambic II, IPA, 70/-
Secondary: Orange Blossom Mead, Flanders Red I
Kegged: Fat Man Porter w/ 1469, Fat Man Porter w/ 005, Centennial Falcon w/ Conan, Centennial Falcon w/ Denny's, Barrel-aged Fat Man Porter, Belgian Dark Strong, Dark Mild