The separation is caused by the VG which serves no purpose in vaporizing concentrates it dilutes the concentrate, causes separation, and provides more vapor which degrade the product. Don't add sweetener. I have tried it, it did add some taste with problems it gives off a burnt taste, the temp of the sweetener vaporizing is not consistent with the concentrate vaporizing. PG USP has a sweet taste. Changing clearomizers can alter the taste sometimes very noticeably. You only want to blend your concentrate with PG USP. You can find PG USP at High Desert Vapes. https://highdesertvapes.com/products/USP-Kosher-Proplyene-Glycol-%28PG%29.html the product image is a bottle of VG, you will receive PG USP. Winterize your concentrate for better taste. Here is a link to my journal. I have a link to skunkpharms about winterizing. http://www.rollitup.org/blogs/blog30912-how-i-make-rso-concentrated.html E-cannabis oil is the best I have ever had compared to smoking buds.