Hey guys, I have a quick question. I currently use a EGO C twist battery with a Kanger EVOD clearomizer on it. When I use expensive liquids such as Halo, V2, etc, I can literally go for 5-7 days without cleaning it and it'll still work perfectly fine. I prefer to use liquid from EC Blend because it is very cheap and it tastes good. However, when I use this e liquid, I have to clean the coil on the clearomizer every 2-3 days or the liquid will turn dark brown, almost black, inside the clearomizer. My question here is, do companies have different quality standards or is this just a coincidence? Thanks for the help guys!