I manage a vape store and just had a customer come in about 2 days ago with some type of cinnamon flavored juice from somewhere, that practically melted 2 tanks in a row in a matter of about a minute. no joke, filled a new tank, he was peiming it and it cracked right in his hands in front of me and started looking like melted plastic, we were both like ...?!?!? filled another, and same result within a minute's time. the tanks were brand new Vivi Nova's, I suggested the Protank as well, and that he probably stop vaping whatever that was cause it's obviously extremely corrosive, he kept the bottle which was like a 30ml size white bottle but he wouldn't tell me where he got it, probably was a failed attempt at home mixing lol, but ended up buying juice from our store. never seen that before happen so quickly