Fixing premixed juice

[Thepinfamily]

Hi,
I'm fairly new to vaping and in my quest to find juice I like I bought some I didn't. The flavors I like but the nic content and PG/VG I don't. I would like to alter them to be more to my liking. I don't think it will be difficult but I would like some advise to be sure I'm buying the right thing. This is what I'm trying to do,
I have 4, 10mil bottles of juice I bought from MBV. The PG/VG MIX is fine(80pg/20vg). The nic content is 18 mg and I've found I don't like vaping anything that doesn't have a TH. I've been vaping 24mg and the TH is on spot. I would like to change these 4 bottles from 18mg to 24mg. I also have several 3ml samples that are 18mg and 4, 3ml samples with 0mg. I want them all to be 24mg.
Second I have two HHV samples I would like change from 100%vg 18mg to 24mg. The PG/VG mix on these do not concern me. They are 6ml samples.
Now, can I just buy a 36mg PG base to bump them all up on nic content or is there a better way? I'm not looking to get into DIY quite yet but that time is coming. Thanks for your help.

 

[glassmanoak]

If you use 36mg nic juice and add to 10ml of 18mg/ml juice, it will take over 4 ml of nic and will REALLY alter the taste. If you use 60mg nic juice, you can add 1 ml of that nic juice and wind up with 11 ml of 21mg juice without the flavor being altered too much. Use a calculator and play with the numbers:
E-Liquid Combining Calculator