"Michi Henning" wrote in message
...


--

"NetMax" wrote in message
.. .

"Jim Morcombe" wrote in message
...
Comments invited. Do I have this right?

I am "often" forced to have too many fish in a tank for a while.

When you add a heap of fish, the ammonia level increases. Most
fish
are
quite tolerant of high levels of amonia, while others drop dead
quickly.

Once comment: if you keep the pH below 7.2 or so, almost all
the ammonia is present as ammonium (the NH4+ ion of ammonia) instead
of as "real" ammonia (NH3). Ammonium is much less toxic than ammonia.
But, of course, once the ammonium (or ammonia) get converted to
nitrite,
the fish will die of the nitrite spike...

Beware that NO3 is a 'silent' killer. Fish exposed to
water shock of greater than 40ppm NO3 will exhibit varying degrees of
discomfort, and the smaller the fish, the more likely the shock will
be
fatal, either directly, or indirectly through Ich or some other
disease.
Nitrate shock is what kills new arrivals (when the rest of your fish
are
fine). IME, death occurs on or before the 3rd day.


Interesting -- I didn't know that. Might help to explain why I had the
odd inexplicable death among new arrivals. (My tank was at zero
nitrates
for quite a while before I wised up and started dosing nitrates -- I
now keep nitrates at around 10-15ppm.) I suspect that 40ppm or more
wouldn't be unusual in many fish shops. I think I'll test the water I
bring
the fish home in next time. Might learn something new that way.

Now, here is the real question: say I just bought a bunch of fish
and they are swimming in 60ppm nitrate. Now, how do I get those
into my 10ppm tank without killing them? I normally acclimatise
new arrivals over about an hour, gradually adding small amounts
of tank water to the bag and then transfer the fish. But I suspect
that an hour is too short to overcome a 50ppm change in nitrates...

Cheers,

Michi.

Good question. A lot depends on the cost of the fish, the size of the
fish and the difference in water parameters. The smaller or more
expensive, or the greater the difference, the slower you want to
acclimate them. Also the conversion from hard water to soft water is
harder than the reverse.

If I'm buying a $100 fish, I show up with a styrofoam box. Inside the
box they put 1 bag of water with the fish, and 3 or 4 bags of only water.
The extra water bags helps keep the temperature uniform while travelling,
and I use it to fill a small aquarium about 50%. This quarantine
aquarium has a small submerged filter, and a small submerged heater (this
allows me to have the water level as low as I like, which often happens
when I'm using partial LFS water to acclimate. Be sure to water test the
LFS water when you get home (from the bag with no fish, as the fish bag
will be skewed due to the CO2 and ammonia released). For 2-3 days, I try
to do nothing, then over the next few days, I start adding my tank/source
water. Your % of tank/source water depends on your tank conditions and
where you want to eventually end up. Laborious.. yes, and it needs the
patience of a saint, but it is very successful. I hope this gives you
some ideas.

cheers
NetMax