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.

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


~ jan JJsPond.us wrote:
Perhaps, but in a pH crash, the filter quits working and the ammonia is
non-toxic in the lower pH. If the water is changed with a higher pH,
without treating the ammonia it turns it toxic. A large water can be very
stressful. IMO, better to treat the ammonia, do a 20% change, check
buffering adding baking soda if needed and add salt if nitrites are
present.

Prior to ALL that. Check all parameters and report, weigh all options
expressed on usenet. ;o) ~ jan


~Power to the Porg, Flow On!~



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