Most decent MTL tanks will work with 50/50 or a bit either way 60/40 or 40/60
Some will still work OK with 70 VG but depends on stock coil
ye olde pen mods were really for 70PG as thin atomizer/coils needed runnier stuff to wick
but better tanks/coils came along and people have used 70%+ VG which is a gloopy juice
(compared to runny 70PG 30VG juices)
Hence the high nic juice £1 LiQuids seemed to be 60% PG so you got a bit more leeway than 50/50
vape88 Maidens Tobacco I started to use when I began is a 70PG juice
but they make a rolling leaf in 70PG at high nic and 6mg nic is 50/50 (I think)
So reason I suggested getting them high nics to give you a 60/40 margin to mess around with
Now this is not written in stone at all - you can probably get away fine with say a 35VG 65VG mix
But before you go nutz establish if you do kinda like the flavour but not too much of it
by simply taking a smaller drag, chew it or something and take it down - yeah that's not bad now
or fuck me nahh that's still fucking minging even in small doses - that sort of thing
(no point trying to polish a turd or messing with a juice you hate regardless)
Flush out tank & coil, give it time to dry, even run a hairdryer over it perhaps to evaporate moisture
BUT you will still have a taint in the tank/coil when trying another flavour
So bare this in mind and give it some time - or you could write off a decent juice tainted with old manky taint
Think the idea is not to dump a juice in there that smells ultra manky to begin with (but you can be surprised)
It's really all a bit of trial n error along with common sense if you tweak your juice
Idealistically you want to establish a decent base juice first is what I mean above all else
if something tastes shit - it will still taste shit but just partially diluted shit
You can only really dilute it a smidge - eg 10ml bottle, remove 1 or 2ml and add 1~2ml glycerin imho
that is altering the ratio from say 50/50 to 60/40 or 70/30 or there abouts
if you dump 5ml & add 5ml you have halved any flavourings and any nicotine
halving the nicotine could leave you climbing the walls
halving the flavour could really leave it feeling a bit too blandish
Don't get wrong ya fucking about with £1 liquids so its no biggy end of day
& I have vaped just VG to flush out a used tank in the past & didn't kill anybody due to no nicotine
(was only for an afternoon but was glad to vape something decent with nic I might add after flushing)
I used to dilute 11mg 7 bottles 70ml of a 70pg30vg with 30ml of vg aprox
I had to lower nic as I was starting to get a tiny bit high chain vaping on the last drag or two
(when I recently switched to a decent tank over a blu pro ecig pen)
yes it was blander but needed to ease up going back to work a bit buzzing from my breaks etc....
think I should have gone 80 + 20vg diluting tbh - yeah was a bit bland but nigh on used all that up now
If you got an empty bottle you can mess about a bit, add a little vg first and retry it
but give it a bit of time to filter through or pass any old juice away
start by adding a smidge say 1ml per 10ml juice and go up to say 2ml maybe 2.5ml absolute tops
I mean there are calculators that can help you work shit out and what you are using now
as long as you got a rough idea of what you started with you can work out the ratio & nic
http://www.steam-engine.org/juice.html
If you finally find "something" even if its cheapo stuff, then let us know on here
then somebody might be able to recommend something similar to it but a little less/more harsh/sweet/fruity/caramelly etc....
edit: getting my PG's mixed up with VG's
the cheapo poundland stuff is mostly higher PG than VG at high strength nic
the drops to 50/50 on lower nic - thought I wrote it correctly but as usual I screwed up in places