plastic vs glass juice bottles, I would recommend glass, but just know that all the VG and PG and nicotine (usually) came in a plastic bottle and had been sitting in a plastic bottle for weeks/months/years.
This is why they say filtered tap water might be cleaner than spring water. But I think it also depends on the plumbing too. If you have PEX plumbing, then the filtered tap water was ran through plastic piping anyway, or older copper piping with lead solder. Personally I still trust spring water more. I hope to think they know what they're doing with plastic water bottles by now.
Yes PET type plastic (the harder, more clear bottles, sometimes juice comes in) is not as stable for certain types of FLAVORING like cinnamon or citric pineapple etc. You want LDPE bottles instead of PET but %95 of e juice comes in LDPE anyway, but sometimes flavor concentrates come in a PET bottle (if you DIY mix e juice and buy flavors).
IMHO the flavor is what will react the most with the bottle, especially alcohol based flavor.
Another thing is temperature change with plastic probably makes it leach more. Example if you store gallons of water in a hot garage and drink them months later. Or similar with e juice (leave plastic bottle in a hot car with windows closed can get like 120 degrees or something). Same with 'microwave safe' plastic storage containers, some are only microwave safe for one or a few uses before they say to throw it out.
With a dropper bottle, gotta make sure it's not sideways otherwise the juice will come in contact with the rubber nipple which IMHO might break down worse than a LDPE dropper bottle. And when drawing the juice up the glass pipette, I make sure it doesn't get into the rubber nipple area. (Also make sure the glass dropper bottle also has a glass pipette instead of on rare occasions the seller might have used cheaper plastic pipettes with a glass tank). Supposedly black nipple glass dropper bottles are safer than white ones. Or vice versa I forgot, the answer is somewhere on this forum. This topic was discussed a lot when there were still plastic tank clearomizers on the market instead of how everything is now pyrex glass thankfully. Cinnamon and pineapple and citrus flavors etc would crack plastic tanks.
IMHO it's not much more inconvenient to use a glass dropper bottle than a plastic dropper bottle. The glass dropper cap unscrews a bit easier than a plastic child proof cap IMHO. If you have a bottle of juice on a desk and leave the cap off, then a plastic dropper bottle would be easier, but you can also just not screw the glass dropper cap on. This is for an RDA use when you are using the bottle a lot, otherwise, I don't think it's much more convenient to use a plastic bottle to "fill up a tank" vs a glass dropper.
Tanks nowadays usually have large fill posts, before it was harder to fill with a glass dropper bottle and I even was using needle tip plastic dropper bottles for some tanks but that's not a problem anymore.
you can get a six pack of glass dropper bottles on ebay pretty cheap, like $6 shipped or something. If it's going to be in the sun, the Amber ones are best (or maybe cobalt blue, I forgot but the answer is somewhere on this forum), but clear works fine if not kept in sunlight (sun light can degrade the flavoring). This is if you DIY juice though and get flavor in a glass bottle I guess, otherwise as stated, it might have already leached if you plan to transfer premade juice from a plastic bottle to a glass one. They have 15ml and 30ml and 50ml and 5ml etc glass dropper bottles.
Some tanks have fill ports so big that you can just use a regular non dropper glass bottle and 'pour' the juice in. Most people use the ones with polycone leak proof lids though, and I guess if you shake the juice, it'll contact the polycone (which seems like LDPE though and not PET).
Another thing is with plastic bottles I can never seem to get them to fully air dry after rinsing between flavors. I shake it so much that I don't think there's any VG left (which won't air dry like water) but they still look like they're speckled with VG when left to air dry for a few days.
Having said all that, I some how realize for some reason I've been using plastic bottles for the past few months. I just changed back to glass. Make sure if you buy glass that the pipette reaches all the way to the bottom of the bottle too, otherwise you gotta tilt it when it gets low.
