Unless you are dedicated to purity and consider tap water somehow not, just use it. If you are extracting DMT, you are creating a FREE BASE. There is nothing from the water, and there should be nothing from any of the other chemicals used, except the alks from the plant source. From what i understand, the minerals in tap as opposed to distilled water are beneficial to the process anyway.
Heck, idk about you, but where i live the tap water is better than a lot of bottled water, comes right out of a natural protected aquifer.
Sine experientia nihil sufficienter sciri potest -Roger Bacon
*γνῶθι σεαυτόν*