On Tue, 6 Sep 2016 17:56:34 -0000 (UTC), "Danny D."
wrote:

As for the ability to hold moisture, I think the water remains by capillary
action, right?

Is there a *test* for that?
I guess I could weigh a pot of the soil before and after watering, and then
weight it a day or two later.

"Moisture meters are used to measure the percentage of water in a
given "substance." Pics: https://tinyurl.com/hfnmgmo

Take the kids to a garden/lawn center on a field trip :-)

To much water and plants could die by drowning.