You will probably get a variety of answers. It's going to be based on your personal taste. I've had the best luck with 1.8 and 2.4 on my vivi nova's on a non vv battery. 1.8 is lower resistance and meant to be used on a 3.7v battery to get a bigger kick from your hit. I'm a menthol vaper with my coffee in the morning, so I use a 1.8 with my menthol, but the rest of my flavors I use a 2.2 for my Kanger EVOD and 2.4's for my vivi nova's. If I'm using my vv
batteries I will use the 2.8 heads and dial it up to about 4v, but it may be different for you. I can't say for the Kanger Protank.... Mine are supposed to be delivered today. But I would think they would be about the same.
I hope this is somewhat helpful

Welcome to the club!
This may be of some use:
