I don't know about the jug water. I always used the machine at both walmart and heb and did it for years. I had a guy on here try to tell me that his water was purer and that he would sell it to me.....I brought him a cup of the walmart water out of the machine and he put his meter on his and then it and they were the same...LOL

He wanted considerably more for his water! LOL

Now I run my own RODI unit so.....can't say much.