It's just distilled water. . . find it at your friendly drugstore or chemical/medical supply store. . . . few cents per gallon. Triply de-ionized simply means that your friendly H2O has been distilled thrice to remove impurities. . . . which may have included some metallic ions, I suppose. . . . but 'triply ionised' sound so much more 'High End' doesn't it? And next they'll call it Triply D-ionized Hydrogen dioxide. . . even more expensive, particularly if also thrice Krioed and filtered through a bed of Tourmaline Granules! G.