If you have a heavy VG juice, you'll almost always have to remove at least one, if not both of the wicks for it to wick properly. VG is just so thick it either takes time to wick or won't fully wick, which leads to burning. So many say not to remove the wicks, though in every single head I've used, both come out. This applies to 50/50 and */50 mixes (where * = 60-90% PG). I've also moved to cotton, as SpyderClouds has. Cotton wicks better and faster that silica in my experience and I now pull out the silica and twist in cotton as a replacement.