wrote in message
...
http://www.ca.uky.edu/wkrec/pH-Ammonia.htm
"Ammonia is toxic to aquatic life and toxicity is affected by pond pH.
Ammonia-nitrogen (NH3-N) has a more toxic form at high pH and a less toxic
form at
low pH, un-ionized ammonia (NH3) and ionized ammonia (NH4+), respectively.
In
addition, ammonia toxicity increases as temperature rises."

A low pH doesnt make ammonia non-toxic, it makes it less toxic. And
toxicity is
increased as the pH approaches pH 9.0.

http://www.ca.uky.edu/wkrec/LimingPondsAquaculture.htm
here is graph comparing the pH shift of hard vs soft water (high vs low
alkalinity).
In sufficiently hard water the pH does not approach pH 9.0.

Great links, thanks. Very informative. I've added them to the directory on
IHMP, http://ihmp.net/@/r.

pH crash (down) is usually brought on by really raunchy decaying organic
material in
gravel or some really serious toxins and is not going to be "fixed" with
ammo lock.
I cant imagine this happening in a pond unless there was no buffer system
OR, the
water is soft and acidic to start with. With acidic soft water dolomitic
limestone
is needed to provide an adequate and stable alkalinity/hardness. In the
case of
sudden pH crash people generally use some baking soda to bring the pH up
out of kill
range, add aeration until they can fix the problem (move the fish out and
clean the
pond and/or change the water and/or add more limestone to stabilize the
hardness).

when there are no test kits the only thing to do when fish are obviously
in trouble
is large water changes, or move the fish to fresh water. test kits may
not show what
the problem is anyway but waiting until the kits can be obtained may be
fatal.

Yes, ammo lock etc works, but I cannot imagine people having that quantity
of stuff
(and costly too) on hand to treat large ponds. People with soft water
need to have a
stash of dolomitic limestone (and dechlor if city water) on hand to treat
the water
during big water changes. Ingrid
snip

I buy ammo-lock by the gallon every year. I have a leak in the stream of my
pond, and therefore and forced to do water changes. So I dechlor often.
IMHO, every ponder, should keep enough dechlor on hand to do a 50% water
change in the case of a disaster. I've had such a disaster and was happy to
have it on hand.

A few examples of such products:

Kordon Amquel, http://ihmp.net/@/u
Kordon Amquel, http://ihmp.net/@/vu
Pond Amquel, http://ihmp.net/@/us

--
BV
Webporgmaster of iheartmypond.com
Check out the IHMP forums, ihmp.net/phpbb
I'll be leaning on the bus stop post.