I found this site and use it to help me adjust nic levels via PG/VG/nic adding. For the flavor difference, I use that and go with 4.0ml flavoring. Its just computations and it helps. As I get farther into making ejuice, I will use it more. Just click on the picture in the upper left. Anyway, A good link.
http://ejuice.breaktru.com/
http://ejuice.breaktru.com/
