Coils vary on what voltage they're used at as well as what juice you may be using. I've had no problem getting a month out of a coil. As far as the mix goes-assuming you're using equal amounts of each, you would end up with 18mg juice. I am able to keep track of what juice is in which mod by using my #ModHolder which has spots for the e-liquid right next to each mod I have the juice in. Did I kinda answer your questions?
At the moment I'm vaping:
Vapor Talk Colada on the Provari
Juicy vapor ecto plasma on the BAM
Vapor Talk Grape on the ego twist
Honest Vapor "buck wild" on the e-vic
and Vapor Talk sweet dawn on the I-Pro
Yeah, I vape a little,
For those of you who don't know me:
http://markspens.com/mod%20holders.htm
I've been making these for quite a while. Scroll to bottom to see some of the finished ones.
Welcome to Vapor Talk and congrats! The smokers cough and other symptom vary from person to person but I've found it can be anywhere between 3 days and a month before they go away but it is well worth it. Good luck on your journey and if you have any questions there are plenty of people here willing to help you.