Soaps may vary in the specific fatty acids used with larger saturated
molecules coming from animal and smaller, mono or poly unsaturated ones
coming from vegetable sources. Castile soap is made from olive oil while
most soaps not labeled as castile are made from mixed animal fats.
Where do you think the slaughterhouse trimmings and the drippings from
McDonald's go? There are bulk rendering houses that extract and purify
the mixed fats. Most soap makers buy the mixed product and would not
quote the proportions of specific fatty acids.
All soaps are detergents but not all detergents are soaps. The detergent
activity of lithium and aluminum soaps used in automotive greases is
limited by their low solubility but they do not disprove the above
statement.
It should not be surprising that there are biological lipids which resist
emulsification by soaps yet can be broken down by other detergents. Fatty
acids have been around for a long time. One would expect detergents to be
more damaging to plants than soaps.
Most soaps contain non-soap materials which may be phytotoxic. Some are
thickened by addition of salt which may damage CP. Dr. Bronner's soap
sold at the health food stores is plain soap, is cheaper than Safers and
has never damaged any of my plants.
Calcium soaps are generally insoluble. One can render Safer's or any
other soap inactive by diluting it with calcium hard water. Try diluting
your soap with distilled water and see if the result is any clearer than
with tap water. If so, use distilled in the future.
Large batches for greenhouse use become expensive. One can use phosphate
ion to bind the calcium in tap water but must take care regarding PH. The
alternative of detergents which are not calcium sensitive may become cost
effective.
Bob Cruder - bcruder@miaco.com
"Hustlers of the world...
There is one Mark you cannot beat:
The Mark inside..."