You can dilute your juice with up to 30% distilled water. Some disinformation here: Soooooo..... There is NO SUCH THING AS WATER-BASED JUICE. Higher than 30% distilled water and your atomizer won't work to produce vapor so its just not possible for any juice to contain more than 30% and the rest has to be PG/VG. PG is anti-bacterial and, unless you're vaping 100% guaranteed VG then there's no worry about bacteria... period. As I said, it has to be guaranteed as most juices do contain some PG due to flavoring and/or nic. I have water-based flavorings I use in food and have never had bacteria grow in any of them... check out the vanilla in your kitchen. If it says "Refrigerate after opening" its probably water-based but most flavoring is alcohol or PG/VG based and fine just in the cupboard.