It does in some water. I am not a chemist either, and I am simply too
old and busy with other stuff to dig out my chem books and start
re-learning what I would need to know to work thru this.

at least in soft acid water using calcium sulfate causes up and down
PH swings. carbonate wont for the reasons you gave. perhaps sulfate
has a much greater dissociation potential (I am grasping at parts of
my memory have not been accessed for nearly 30 years!)

It is like people used to recommend vinegar to acidify the water. Good
idea, but it is organic and soon the water contains enough bacteria
that uses acetic acid as a food.

Ingrid

On Sun, 13 May 2007 15:06:57 CST, Derek Broughton
wrote:

wrote:

dont know, but when those "pills" are tossed into soft acid ponds the
pH swings are enough to start killing the fish. It sounds good in
theory, just doesnt work. Another Koivorkian moment.

You're a scientist, Solo; you should know better. Plaster of Paris does not
cause wild pH swings. It sounds good in theory, _and_ it works. It
doesn't work in the _long_ term because the buffer gets used up, but it
does work.