Make your mix of em crystals to pga or pg by volume not weight. 1 tsp=5ml. A little heat (hot water bath - coffee cup with some hot water) will help. Treat that as a flavoring. To be honest I bought a couple ounces of the cotton candy pg, which is a 10% EA/PG mix, from PA when I first started thinking i would use it. So far I have not needed it. I can not tell you if is because I mix at a 25-35% vg or if the flavors I am using are sweet to begin with.
A good starting point would be to grab Scubabatdan's calculator from the stickies in this area of the forum. I worked up my own and from that have a better appreciation and understanding of what he did. The nic content can be thought of in simple terms as mg per ml. If your starting with 100 mg/ml and adding 1 ml of that to a mix that will be 4 ml in the end you will have 25mg/ml. Sorry for the over simplification but it gives insite to how the calculators work. They take the final volume and figure the initial addition of nic juice by mg/ml to arrive at the end product. The calculator will want the starting mg/ml of the nic containing liquid, the finish qty and the other various percentages. Give up on getting the perfect vg/pg ratio right away unless you want to go crazy. You have 100 mg/ml PG mix and only vg to add to it from your original post. For a 4 ml mix at 25mg/ml with 15% flavor you will have 2.4ml of vg and get a 60% vg to pg ratio. I have a bottle, mason jar, of 50/50 mix that I use to dilute the base nic with. For low percentage flavor mixes I end up with more vg and vice versa. But it hovers around 25~30% vg. That is fine with me.
You can get as exact as you like but I suspect over time you will find that somethings are not really worth the attention. I focus on the flavoring percentage and let the pg/vg ratio ride at that 20-30% for now. Excel and the goal seek tool could be used to find the exact ml's to get the 25% vg at 17.2% flavoring and all that but in the end I do not think one can really taste the difference. Think more cooking/seasoning and less apothecary perfect mix.
In all honesty... I have tried several flavors and found some I like at a random percentage based on how strongly they smelled when I opened them for the first time. I am not some master mixologist by any stretch. I smell, mix, vape, wait, shake, toss in a coffee cup of hot water, vape, keep vaping and after a week if it still tastes good call it a good recipe. So far I have like 2 maybe three that I would mix without thinking that I would have to tweek it later. If nothing else I have learned that this is far from an exact science. Play with it and enjoy!
