Tynk:
Keep a close eye on the other fish it was housed with. He got that
bacterial infection for a reason and until you figure out the *why*,
you may not be done with it.
Are you keeping up on regular water changes?
Were there any new fish added without quarantining them?

Good info. Yes I had added fish to the tank. Here was the sequence of
events...
1. Bought a 4G Biorb for my betta who was in a .5G tank my wife had
bought for him.
(I found out after the fact that people seem to hate these tanks but it
seemed perfect for the betta and probably would have been if I had left
him alone)
2. After a couple of weeks I decided to add some fish, so I added two
rasboras and a panda cory, didn't know about quaranting yet.
3. Cory died within hours and I thought maybe it was a fluke. Changed
the water, washed the bowl & contents with hot water and replaced fish.
4. betta got sick the next day, I separated him and treated both tanks
with Jungle Clear (which in my defense does say for fungus and bacteria
on the label) and he died late that night.
5. Two rasboras died two days after with no signs of infection or rot.
Another rasbora was swimming in a spiral motion so I took him back to
the pet store and they said they would try to save him. I changed half
the water but did not retreat with Jungle Clear.

I figured the other rasboras would die but they didn't. So far they
appear healthy and strong but so did the others right up until they
died. The rasboras that are alive don't seem to have much of an
appetite. They nibble a bit but not much. I've been feeding them once
per day. I plan to change 20% of the water in a few days.

I just checked the water quality and everything was fine except Nitrites
which are starting to rise again so I added a conditioner made by Prime
to remove ammonia and detoxify nitrites and nitrates until I can do
another partial water change.

--
Mac Cool