A. Distilled water will reduce maintenance requirements.
De-ionized water can be used in a pinch but NOT recommended.
Do NOT use tap water. Tap water is full of impurities.
Water turns into Brown’s Gas (a mixture of hydrogen and oxygen), which leaves all the impurities, that are in the water, to form sludge in the ER HyZor. The sludge will inhibit the efficient formation of Brown’s Gas.