I have been with a very reputable juice maker for quite a while but my last 2 orders have me confused. I do not want to badmouth this supplier because until now I have been very happy with their products. I have a bloog maxxfusion & volt batteries and use their carto's but lately after 1-3 fills the liquid is turning into this nasty black tar like substance that comes to the top of the carto. The liquid is (almost) clear out of the bottle and I've tried V4L cool carts, bloog, & SI cartos all with the same results. Anybody else experiencing this or is it just me? juice is 30/70 PG/VG.