SS wrote in news:lTHxg.245733$IK3.7409
@pd7tw1no:

My 55 gal has been hit with NTD, Cardinals and Glowlights all gone, only
my little zebra danios left. Do I have any other options to rid my tank
of this disease short of tearing it all down?


Are you sure it is Neon Tetra Disease? The scale of death suggests F.
columnaris bacteria to me. NTD is not limited to tetras; it can affect
barbs, rasboras, angelfish, and probably many others.

NTD is caused by an internal sporozoan parasite. No one really knows how it
is transmitted, but many suspect that it is through ingestion of infected
tissue (i.e. the eating of dead infected fish). The progression of NTD is
generally slow and it can take a relatively long time for a fish to die
after the first appearance of symptoms. There is no effective treatment
other than to remove and euthanize the affected fish before the disease
spreads to other fish--this generally controls the spread of the disease
quite well.

An internal columnaris infect looks superficially like NTD but the time
between the appearance of symptoms and death of the fish is much shorter
and spread of the infection is generally much faster. F. columnaris can be
treated using anti-bacteria chemicals or by using gram-negative
antibiotics.