*kr808dl -
I've been using liquid Stevia and powdered Trehalose (both purchased from Swanson's Health products) as well as VG for about 3 weeks now.
I've experimented with mixing the Stevia and Trehalose with distilled water, unflavored nic juice and added flavorings. I've used Stevia and Trehalose separately in juice with distilled water and VG.
I've used the same 901 atty with blue foam filler with the sweetner and so far, my atty is doing good. I blow it out once and a while and it's still good to go.
I don't have exact formulas but have found that I add 1 drop sweetner to a 15 ml of nic juice. It's not too sweet. Over time, the sweetner and the flavors get better or at least seem to taste better and sweeter.
The most I've used is 3 drops per 15ml and it was barfo sweet.
Here's a link on Trehalose:
Trehalose: Sweet Rescue
And one on different sweetners and their properties:
Sugar substitute - Wikipedia, the free encyclopedia
I have read that there is concern about vapping "sugars", but from what I have researched, it seems that the concern is when inhaling large quantities of sugars. Kind of like the experiment that diet coke gives you cancer because lab rats that consumed 2,000 times the normal amount got cancer. As with most things, moderation and caution should be used.
Hope this helps some.