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RE: [Killietalk] UV irradiation ... WAS ... Flow thru systems
Hi John:
Your argument was proposed long ago in the saltwater community. Some people
thought that sterilizers both ozone and UV would eventually have the effect
of creating immunodifficient fish. It was as invalid then as it is now! Let
me assure you I am writing from personal experience. Before I continue, let
me apologize for the tone of this missive, to some it might appear
uncharacteristically harsh, and so it is intended. This is a myth that
should have been laid to rest a generation ago and should be quashed before
it kills any more fish.
I worked without the sterilizer while a friend bit the bullet and bought
one. I have been long out of the salt water hobby, having lost hundreds of
dollars of fish at a time, while he has had tanks run for years without
trouble. I might add that when my friend is not adding new fish he has
often turned off the sterilizer for extended periods of time without unusual
disease outbreaks. We have seen no evidence of unusually weakened fish due
to sterilizing the water.
You see the relevant issue is not the fish's immunity. It is the
concentration of pathogenic organisms that can occur in a fish tank. In
nature, pathogens exist at very low levels. Some fish get sick and die,
others get better and develop an immunity over time while others never get
exposed to the pathogen. In some cases fresh water pathogens are confined to
geographic localities as bodies of water are separated by land masses or
even oceans. Fish that come from areas where the pathogen exists have over
generations developed some immunity.
In a fish tank, pet shop, or fish wholesale we combine fish from all over
the world and diseases are easily spread. Next, in a fish tank the pathogen
is concentrated to levels that may be thousands of times higher than they
occur in nature. There is no way a fish will survive long enough to develop
an immunity to many fish diseases.
I'll add a salt water antidote. With Oodinium (salt water velvet) a single
organism reproduces to from many juveniles. In the open ocean, there are
predators that would filter out free swimming microorganisms. Then there are
trillions of gallons of water for the offspring to diffuse into. Many die
without ever finding a fish. In an aquarium, each and every offspring has a
high likelihood of reaching a fish and restarting the reproductive cycle.
If you have ever seen an Oodinium blossom in a salt water fish tank you
would understand. In a matter of hours all of your fish are dead without a
sterilizer or the addition of copper formalin to kill the parasites. In
most cases, a sterilizer will not cure an Oodinium outbreak, just slow it
down until it can be treated.
Finally, if you have more than one tank on a recirculation system without a
sterilizer you are running a real high chance of wiping out all of your fish
with the introduction of a single pathogenic organism. The sterilizer may
not be 100% effective, but it is far better than nothing. The myth that
fish that live in a healthy environment may have less tolerance to
pathogenic organisms may or may not be true. But I can say with every
certainty, derived from personal experience, that it is irrelevant. Ask
yourself two questions: Are you trying to develop disease resistant fish or
are you just better off keeping your fish in a healthy environment? And
would you expose your children to full blown smallpox or plague in hopes of
their developing an immunity?
Peace,
~RJ~
-----Original Message-----
From: killietalk-bounces at aka_org [mailto:killietalk-bounces at aka_org]On
Behalf Of listhub at libros_andante.mn.org
Sent: Wednesday, January 14, 2004 8:44 AM
To: killifish discussion list
Subject: [Killietalk] UV irradiation ... WAS ... Flow thru systems
Barry,
First let me thank you for your response to my email and I am sure we will
all
benefit from the article you and Lee are creating.
Now to a comment / question ... and I hope this prompts a few comments back
to
Killietalk because it is something I have debated over the years, both with
my
killies and my bettas. The fact that I have a high respect for your fish
keeping
expertise as well as for the general level of expertise on this list, makes
it
seam like all the better place to begin this discussion.
On 14-Jan-04 Barry Cooper wrote:
> This required UV irradiation on each rack and I still didn't seem
> to find the time to change the water in the sump, which was the original
> idea. I also had a feeling that my fish weren't doing as well as they
should.
>
Could not UV be a bad idea??
Here is my reasoning. Fish build immunity just like all other organisms.
The
literature I have read seams to indicate that much of the immune response in
fish is in the outer slime layer.
Are we producing an environment with UV that is hindering the production of
a
healthy immune system. As I am sure you know, as does anyone with much Bio
training at all, the rule is no antigen no antibody. This could be
especially
hazardous when we have a fry grow out system and use UV on that and then
breed
the adult fish in environments where there is much more for their now, less
the
full formed, immune systems to handle. Even worse, IMHO, is shipping 3
month
old killies, raised under UV, to someone, especially someone new, who might
not
be doing the rigorous water changes that need to be done. In short the
question is are we producing weak fish using UV irradiation in grow out
setups???
Ok list, have at it!
Peace
john
------------------------------------o------
John N. Alegre o
Andante Systems o
eCommerce Consulting o
Custom Web Development <*{{{{}><
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