Mark wrote >Water treatment plants are required, at least in America, to discharge >water above pH 7.4. Low pH and high dissolved oxygen increase >corrosion of lead solder in old pipes which is a public health concern. The one that feeds my new home (with water from the Clackamas River) doesn't. I know because I just filled and tested the hot tub, and I had to add quite a bit of chemical to raise the pH enough. The low pH of my well water (delicious pure water) at my old place affected the copper pipes some and a plumber installed a device to correct it. I have a rainwater storage tank (1100 gallons) that captures runoff from the bulb house, and then I siphon the water out with a hose to irrigate the bulbs. I also mix the fertilizer with it. It is slow, and I should probably have an electric line run out there so I can install a pump in the hose line. Yes, I am too lazy to set up an extension cord every time I want to water the beds. I use tap water on my seedlings and other container plants, not to mention the irrigated parts of the garden, and I don't see any damage on plants or mineral deposit on the pots. Does rainwater really have more "air" (gases, which ones?) than tap water? I've heard that snow does, and that if you pile snow on your seed pots and let it melt there, it will enhance germination. I don't know if it's true, but I do it anyway when snow is available. Jane McGary Portland, Oregon, USA