> the fish are sick, they have pathogens on them.
>
Thanks Craig,
Not only are the disease organisms on the fish (as in Ich, Velvet etc) but
they are often IN them too (as in TB etc) and so the organisms will only
pass through the unit if it is in the free-swiming stage of the life cycle
( remember that Ich parasites are only treatable with chemicals in the
water at this stage also) or being discharged from the host fish ( as in TB
with open lesions or from the gut etc) and it would be naive of us to
believe that the efficiency of the filtration plus UV is such that every
single disease organism would be miraculously sucked away from the host and
into the unit to be destroyed before it could come in contact with another
as yet uninfected fish in the tank.
The old dictum that a sick fish means a sick tank until proved otherwise
still holds and Craig's advice about the "stress" factor in illness is
paramount. Careful and considerate selection of inmates, good maintenance
as in regular water changes, not over-feeding, appropriate temperature
range etc as well as quarantining of all new arrivals will help avoid
disease better than all the gadgets under the sun.
Perhaps there is a place for a UV sterilizer in a quarantine tank setup but
then you already have the fish in a situation where they cannot infect your
others ;-)
Cheers
Bruce Hansen