Sorry, I gotta disagree. I've kept tanks of variouse sizes - from 5 gal to
many thousands of gallons, in both marine and fresh water setups. I've had
tanks since the mid 70s.

While it *may* be possible to set a tank up and get it running without
losing any fish (or damaging their physiology with water chemistry changes
as the tank settles in), it is much more realistic to expect to lose some
fish. For the tanks I keep for recreation (as oppsoed to commercial breeding
or research tanks), I have the luxury of being able to start the tank up
slowly, and can start out with fish that I really don't care about (feeder
guppies). It makes things a lot easier, faster, and in reality, I only lose
one or two with each tank startup. The rest end up as food for the real
fish.

For the tanks that I don't have the time (or it is not economical) to do a
slow startup on, I seed the tank with media from one of the established
tanks. This helps, but it still takes a while for the chemistry to settle
down. In these tanks, where the fish that are going to be in it are often
irreplaceable, I have absolutely no problem stocking heavily with trash
fish - the type of "trash fish" depends on the size of the tank - I'm not
going to bother with feeder guppies in a tank thats bigger than most ponds,
and they certainly are not appropriate for marine tanks (I like to use
squalus acanthius as the trash fish for the larger marine tanks)....

the simple reality is: by putting fish in a tank, you're trying to create
and maintain them in an artificial environment. If you can convince yourself
that he environment you create is really comparable to a natural environment
(and that the "natural environment" is really the ideal environment), have a
blast. If, on the other hand, you opt to be a bit realistic, and recognize
that at best any tank you set up is a poor model of a "natural" (polluted or
otherwise) environment. Unless you live someplace that you can set up a
flow-through system, you are creating an environment that is inherently
unstable, and will place artifical stresses on the tank residents. I simply
choose to accept this fact, and during the most stressfull tank time
(start-up) accept the fact that there is a lot of physiological stress that
will take place (no matter what you do). I choose to allow fish I don't care
about experience that stress instead of the fish I *do* care about.

As for determining the maximum carrying capacity of a tank, you can run all
the tests, monitors, etc that you want. The only way to truly determine how
the species of fish that you are keeping will react to the myriad of water
chemistry issues that are inherent in a tank is to experiment. Yes, this
will definitely cost you some fish. Yes, this will also place a lot of
stress on the more sensitive fish (assuming a multi-species tank) in the
tank. Thi sis an yunfortunate reality of maxing out a tank... If you don't
like it, don't max out your tanks.
As a side note, the best monitor I;ve found for water chemistry is a fairly
sensitive fish. Pick something that is sensitive, but fits the environment
you are setting up. If its more sensitive than the fish you are keeping, it
will let you know thing are out of whack before the inmportant fish are
overly stressed. (Yes, I do monitor water chemestry - I have (and use) all
of the resources of a full research lab available to monitor water quality.
Doesn't matter. canaries are still the best alarm systems for coal
mines....)

--JD


"amosf © Tim Fairchild" wrote in message
...
jd wrote:

*SNIPPAGE*
Get the tanks set up, and throw in a bunch of trash fish (feeders).
Watvch

Trash fish. hmm. So what do you do with the trash when finished?


typically, I feed them to other fish. Alternately, use something that you
might be interested in keeping as trash fish. My standard is feeder
guppies. If some survive, they become a food source (both adults and fry)
for the fish I get once the tank is stable.

I was just wondering since it's likely any fish you use for cycling will
be
damaged in the process. And fish are fish. I guess using the term 'trash'
fish suggests that they are fish that you aren't required to treat with
the
same care you would a non-trash fish.

Anyway, doing a fishless cycle or getting some media from another tank
solves that issue. Start without fish until you have bacteria to cope with
the bioload, or with media, start slow with the fish you actually want in
the tank.

Get the tanks set up, and throw in a bunch of trash fish (feeders).
Watvch
your water chemistry until it stabilizes, then add fish until its
saturated
(can't support any more fish). Now, turn on the UG filter, but don't
change
anything else. Watch your water chemistry change for the better. Now, try
adding more fish, and see how many more the tank will support now....

This part is bad advice. Period. Throwing a bunch of fish in there to
suffer. 'Saturated'? What the hell does that mean. You put a bunch of fish
in a tank with no biofilter then the ammonia levels will climb
continuously, damaging gills all the while, eventually to fatal levels.
There are no bacteria to support ANY fish at all. Even if you then start a
filter after the ammonia spike and by some luck the bacteria take off and
drop ammonia levels and you add even more fish, then the nitrites will
spike and kill them.

Watch the water chemistry until it stabilizes indeed. Watch the nh3 and
no2
climb through the roof you mean...

Enough new aquarists end up with fish in ammonia soup without that sort of
advice.