I've been using my Aspire Odan 7ml tank almost exclusively and just topping it off when it gets down a bit to keep the Coil wet. Last night I noticed that it's getting a little yellowish/goldish. It still tastes OK but I'm wondering if it would be better to take a loss and start over fresh once in a while. What do you think? Is it a good idea to keep filling it over and over for months or at what point would you start over. I'm not all that concerned about losing say 3.5ml of Nicotine if health wise it's a better idea to start clean. Thoughts?