if you mixed pond water into the bag water that could have caused some gill
damage.
koi are all "carriers" of stuff. they get into an immune balance with their
cooties and are asymptomatic. but when STRESSED, the cooties break out of
dormancy or control. then the stressed fish is fighting to control it AND
becomes an incubator that spreads the cooties to the other fish. when your
existing fish are infected, they become STRESSED and their cooties break out
and spread to the new fish. this goes back and forth until it finally
settles down.

if none of your fish die, you are lucky. NEW FISH MUST ALWAYS BE
QUARANTINED. water from the pond they are going into should be used halfway
thru the quaranatine to introduce them to cooties they might not have had
contact with before. it is infinitely easier to treat a 100 gallon stock
tanks than a big pond. cheaper too. AND, the stock tank can be heated to
speed recovery for some infections.

gasping is always an indication of impaired ability to get oxygen. it means
the gills have been attacked by something. attack always starts with
parasites, ich, gyros, dacs, something like that and then come the bacteria.
bad slime coat is either water condition or parasites. since the PP seems
to have worked it is more likely it was gyros, altho the salt could have
helped with ich. in koi ich causes the skin to look like it has a rash.
the white thumbprint suggests columnaris.

SPRING IS NOT THE BEST TIME TO GET OR MOVE FISH. fish are most loaded with
crud in spring. moving the fish to a 29 gallon will most likely kill it. a
big 100 gallon stock tank is best for koi quarantine, and a nice big gravity
filter to keep the water pristine. Ingrid

"humBill" wrote in message
2 Saturdays ago I was given a 15 inch domestic koi
I floated the bag for about 30 minutes and then released him.
For about the first five days it seemed just fine
Starting about 3 days ago it is obviously in great distress and dying. It
stays at the edge of the pond, gasping and has difficulty even staying
upright.
some slime coat thickening as it seems it is literally dirty on its top
side.
gill covers look like they have a giant thumbprint on them in white.

2 days ago I notice a few of the fish flashing. One small one even jumped
out of the water, so I thought well maybe it's unknown parasites. I
salted
to .1% that evening and dosed 10 gms of PP for my 1000 gal pond yesterday.
Though it isnt obvious to me I must have more 'organics' than I thought as
I
actually dosed 3 times and each time the sample was virtually clear within
an hour or so. I have not dechlorinated in 10 days minimum.
he will dive, but then come floating back up when I move.
As mentioned 1000 gal - 13 fish - 4 koi (2 5", 1 about 11 inches and
the
sick guy) and the rest comets 3-6 inches.
water temp 68 and I have been
lightly feeding. About the only thing I could move the koi to is a
currently dry and empty 29 gal aquarium. I have wondered if the flashing
is
of significance with the koi. The koi actually came from the botanical
gardens, which has definitely had problems with their water parameters in
past months, hence them giving away fish to lessen the load