What kind of water do I use to water my amaryllis?

Regular tap water is fine for watering amaryllis. I have grown them in a standard potting mix (which contains peat moss), and I have also grown them in unmilled sphagnum moss. I prefer the unmilled sphagnum moss because it looks better and the bulb seems healthier and less prone to disease. It's more costly, but if you're only growing one or two, it shouldn't be a big deal.