I would check into that and find out exactly what's in your purified water. If it is like reverse osmosis, where all the metals and trace elements are stripped out, then you need to add CalMag or something to make up for it. Iron, zinc, all that stuff is important. I use well water just fine. Most people use city tap water just fine if they neutralize the chlorine either with drops or by letting it sit out for about 3 days so all the chlorine can evaporate.

I don't know what the difference is between distilled and purified. Try running it through a search engine.