There are many arguements against the plastic water jugs. But, there are some for them too. I posted a similar question & have done a little research.
Some say: Don't use them for more than a month. Others say don't use them at all. One member posted that he lived in a country that glass carboys were not available & he had always used plastic with no issues.
If you do some searching on the triangle number on plastics you'll find some descriptions. The one I find interesting is the #1. Better bottles are #1 plastic.
Everyone is boasting about the "better bottle" I don't quite understand this because they are not much cheaper than glass & you can not vacuum these bottles. In some senarios glass is cheaper. Some arguments for the better bottle are they are lighter & don't break. And, for some this may be worthy of discussion, but for me it's not. I can pick up a full glass carboy & i'm carefull enough not to break one (yet).
Secondly, the better bottle is a number 1 plastic. But, Glacier Mountain water bottles(mostly) are also number 1 plastic. And, I have found absolutely no information that shows how a better bottle #1 is different than any other #1 plastic. (I will not get offended if someone proves me wrong) maybe I just didn't do enough searching.
At this early time in my wine making, I prefer glass mainly due to visability of the wine & ability to vacuum. But, if all you have is a plastic water jug & want to use it, I don't think it will hurt (as long as you use a safer #, especially a #1). But, hey, I'm just a newbie.
My thoughts,
Brian