To help with the math:
Your entire liquid volume is 100%, so if you figure in the neighborhood of 20% total flavorings (e.g. the Tiger's blood recipe I use is 7.5% Watermelon, 7.5% Strawberry, and 2.5% Coconut - that's 17.5% total liquid volume) and flavorings are mostly PG-based, you only have room for 12.5% unflavored PG to make up the rest of the 30% TOTAL PG volume. The rest depends on what nic level you're trying to achieve and what your nic base is. Let's assume your target is 18mg, and you have 36mg VG nic
PG - Strawberry - 7.5%
PG - Watermelon - 7.5%
PG - Coconut - 2.5%
Subtotal PG flavors - 17.5%
Unflavored PG - 12.5%
Total PG - 30%
You want a total nic level of 18mg/ml from a 36mg/ml base, you need 50% of TOTAL volume to be nic
Total VG Nic 50%
You're up to 80% total volume, so you need 20% unflavored VG to make the balance.
Long ramblings summarized:
PG-based flavorings - 17.5%
Unflavored PG - 12.5%
36mg/ml VG nic - 50%
Unflavored VG - 20%
Should yield a 30p/70v 18mg/ml juice.
ETA - the calculators are great - I'm just a geek and like doing the math in my head
