Ok guys, I've been loving my aerotank, but I'm having a problem with the coils. The first one lasted about a week which was normal, but the second lasted about 3 days before it got all gunked up and black. I tried rebuilding it using a single coil but couldn't get the wick right and my Provari kept reading error messages (I will have more time to rebuild this weekend). So for the time being I put a protank II coil in and it works great. Any idea why the coils aren't lasting like they should?