I am relatively new to vaping and refilling cartos. I have a bunch of Volt cartos that I have refilled about 7 times, but I started just refilling the same two or three over and over and left the rest unfilled for a couple of weeks. I have now started using those, and I am finding they don't seem to last too long before they start to taste burnt. Was it wrong to leave them unfilled for that long? Should I keep cartos filled all the time and not let them dry out like that?