Hard water on bulb containers in greenhouse.
Kenneth Hixson (Fri, 02 Oct 2009 13:54:15 PDT)

Hi, Marguerite

I need some advice about hard water from my well.
I have
always read that the water softeners commonly used on houses will kill
plants.

A websearch turns up lots of information, for instance

http://ag.ndsu.edu/pubs/h2oqual/…

One of the quotes is

For every grain of hardness removed from water, 8 mg/1 (ppm) of sodium is added.

This is fairly typical of the old types of water softeners, which
mostly used salt (Sodium chloride). There are a number of
newer types, and it might be worthwhile to talk to someone in
your neighborhood who installs wells and treatment systems for
the particular minerals in the water in your area.

Saving rainwater: As much as possible, which means a
big storage tank. The amount you normally receive as precipitation
and the amount of roof area available will determine the size of the
tank. If you collect from your roofs, the first rain will probably wash
a lot of dust off the roof, so you might be reluctant to save it, or
perhaps divert it to a small secondary tank that can be filtered.

Ken