it isnt the same stuff, most likely. I will say tho, that when we
fill our big ponds out of the well at the dacha the water has a
definite whitish cast.
it may be possible to remove a lot of that "stuff" with aluminum
sulfate aka alum.
if your pond is very warm, that algae can suck the CO2 out of the
water at night right along with the oxygen.

the HARDNESS (forget carbonate for now) is due to calcium and
magnesium. oysters only have calcium. but they both do the same
thing. they are the main buffering ions, but you can try putting some
baking soda, sodium bicarbonate in to increase the carbonate buffer.

I think it would be good to start with what is your water like out of
the tap???

can anybody remember the url for the florida state article on this
topic? Ingrid


On Tue, 8 May 2007 13:00:33 CST, Joan wrote:
The stuff I used is called dolomite lime. It contains mostly calcium
carbonate and magnesium carbonate.

The pH has been fairly stable from day to day and is ranging from 7.5
in the AM to 8.5 at the end of the day. I am also having a big algae
bloom, and I have some elodea, so I think that is partly responsible
for the swings. I also have barley bales in there and I'm netting out
what algae I can.

My buffering capacity is still on the low side, so I got some oyster
shells for koi ponds and have them in a bag. So far, so dramatic
change.

I am trying to do whatever I do *carefully* and *slowly* and only
after a great deal of thought of the pro's and cons. Oy.

Joan

did you get a pH on the water? landscape lime could be quicklime and
drive the pH up over 8.
you need dolomitic limestone, it is almost like sand, off white with
dark gray flecks, a little course. Ingrid