I used distilled water to get clear balls of ice that are quite lovely in the glass or the moscow mule mug. I detected no aftertaste as some have reported. I wish i had purchased the 2" molds - 2.5" is bigger than you might imagine. Still, it was my choice. These balls of ice will make for fun conversation when company comes! The only suggestion i have to offer is that the vendor should offer the number of ounces of liquid to use instead of a 1/3" clearance. You cannot see how full it is because the mold must be assembled before adding liquid, so it is trial and error for the perfectly round balls of ice.