GardenBanter.co.uk - To Quarantine first fish in tank... or not?

"Harry Muscle" wrote in message
...
I'm gonna be setting up my new 55G planted tank soon, and I'm wondering
if I
should quarantine the first fish that I will introduce ... which will
be 3
SAE, & 6 Ottos. I know that the pro for quarantining the first fish is
that
it's cheaper to medicate them if needed in a smaller tank. However, my
main
concern is ... is there a chance that these fish might carry something
that
could infect other fish that will be added later on? So for example, I
add
my 9 initial fish to the main tank, they are fine, no signs of illness,
however, something that they had makes a home in my tank, and then
infects
fish that I add later on (which went through a quarantine period).
Hope
that makes sense. So could the above scenario happen, and could it be
prevented by quarantining the first fish?

Thanks,
Harry

If your introduced fish bring a contagion which does not affect them, how
would you have detected this in a Q tank? There is merit in quarantining
the first lot, especially if: i) a purchase looks suspect or came from a
suspect tank, ii) you are mixing established fish with purchased fish
(the susceptibilities of established fish go to both extremes), iii) if
the tank is highly planted or rock-scaped, and there is the
impracticality of treating large tanks for bacterial contagions (treating
parasites is usually cheap).

The reasons not to could be iv) too many different purchases to be able
to quarantine them all individually, v) all came from reliable sources
and are in excellent condition, vi) you are willing to take the gamble.

FWIW, I stock my African tanks all in one shot. I collect all the fish
(usually juveniles) I want from various stores, putting them all together
in a holding tank (bare-bottom, no rocks, plants or decorations to fight
over). Within 2-3 days, everyone is collected and if there are no
obvious problems, they all go in at once, so the entire tank is
effectively a quarantine tank. Then I try to leave it alone for a few
months. I cycle by moving filters around, or fishless cycle as needed.

ps: Because different species have varied susceptibilities to diseases,
your probability of a tank contagion increases with the total number of
species mixed together at the same time (if you were on the fence, this
might help you decide). A compromise might be to isolate your fish by
species, but I tend to put more effort into observation and quick
medication, than relying on quarantining, but ymmv. Once the tank is
established, the rules change, and all new introductions (fish, plants,
snails etc) get quarantined, or else I'm ready to face the consequences
of what goes wrong. hth

NetMax