I have a couple questions about using titanium coils on a TC device. I am using a IPV3Li at 450 degrees and 60 joules. I am getting a great vape from these coils but they seem to get dark quick, I can't tell if its oxidation, juice build up, or just what occurs after a few days of vaping. I am using a pretty sugary juice but the coils are turning black, no grey just black. It also seems like I have to turn up the power every few days to keep up with my sweet spot, is this normal with titanium? I am sure its Grade 1 pure titanium. Can anyone help me get to the bottom of this.