Probably best to get those atomizers out of your Nautilus... stop vaping them.
They have a special filler material which eventually goes bad. Normally, this happens and it's clear what's going on, as you'll get a bad taste and lots of gurgling (possibly).
30-40ml of liquid is when it normally happens for me.
Some people won't use BVC coils. I like them, but think the sensible thing to do is take them out earlier rather than later.