Re: [APD] pH shock

[Wright Huntley <whuntley at verizon_net>]

Bucks_Boogie at webtv_net (Rob Dotzler) wrote:

> I strongly disagree with pH shock being harmless.  I have found pH shock
> to be the most common reason for premature death after "Water Quality",
> ammonia and nitrites.  The only thing is, it takes 1-2 weeks to kill the
> fish.  Especially fish that are delicate like neon tetras or anything in
> the pleco family.  After 10 years and thousands of customers water
> tests, that is my conclusion.   

What else were you testing when you tested the pH?

I have routinely subjected very, very delicate fish to sudden pH changes 
of more than 2 full points with no short *or* long-term effect. [Col 
Scheel, in his Atlas of Killifish reported 3 points as also being 
utterly unimportant. I've never had reason to test that much swing.]

> While I'm no scientist, I can
> comfortably state I am an expert on basic water tests.  

You probably are way ahead of the chemical morons who write fish books, 
though.

> Of course, they
> all come in for a test after my second cup of coffee and I need to hold
> the test bottles with both hands, like a cop taking aim.....

Just like me trying to hit this slippery keyboard, right now. :-)

"Post hoc, ergo propter hoc" is still really popular in aquatic realms. 
"After this, because of this" is an old logic fallacy that we all fall 
for from time to time. 90%+ of the times I have seen a "pH-shock" 
problem, it turned out to be an osmotic-shock problem. That is, the tds 
difference caused the skin and gill cells to be damaged before the 
osmotic regulation system could fully adjust. It was a coincidence that 
the pH was different and the sudden dissolved solids change was the real 
culprit. [Slow acclimation allow both pH *and tds* to change gradually.]

The other 10% or so were because the water contained a lot of ammonium, 
and the pH was increased to 7.5 or above, releasing a little deadly 
ammonia. A "lot" in this case is 50-100 ppb or so, and way, way below 
what can be tested with the worthless lfs ammonia test kits. This one 
can cause long-term stunting and other damage that may not be apparent, 
right away. Gills, particularly, are damaged.

I am unconvinced that pH change is the cause of what people still call 
"pH shock." If they routinely used a tds meter (as many modern aquarists 
do), they would quickly change their minds.

Wright

--
Wright Huntley - Rt. 001 Box K36, Bishop CA 93514 - whuntley at verizon_net
                    760 872-3995

"Outsourcing" is condemned for sending a few American jobs overseas.
What is the appeal, then, of "outsourcing" our entire national security?
[The exact same politicians are insisting that it be handled only by the
UN, and never by our own resources.]       -- WH


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