I think from previous discussions (mainly Adrian's comments) the Aeromonas type
ulcers strike very quickly and usually kill the fish within a week. The TB
type ulcers are slow and very painful to watch. It can take 6 months or more
unchecked. If you work fast enough you can get some eggs. It would be best to
do so as soon as possible. All of the ulcers that I have seen take a long time
to kill the fish.
I believe that TB has been around in the aquarium waters for quite some time,
it's just that bows are much more susceptible to it. I remember reading
somewhere where someone said that ick (Ichthyophthirius) is always around, even
on healthy fish. Give them a good stress and you'll see it in the tanks,
especially on susceptible fish like black mollies etc. I think the same thing
might apply to TB, with rainbows being the most susceptible. It also depends
on your water chemistry and how often you do water changes, fish load etc. I
don't know for sure the water conditions of the Seattle Washington area, Dan
but my recollection was that it was quite soft, in the 80 ppm general hardness
area. I would bet that the carbonate hardness is equally low. This is the
perfect setup for ulcers, especially if you have a high tank load and not doing
lots of water changes (50% every 2 weeks is what I would suggest for anything
under 150 ppm). So far this theory has held true to course here in the states.
When I talk at areas that have water harder than 220 ppm general hardness,
essentially no ulcers, unless they've really messed up with water changes. In
areas where the water is below that, you have varying degrees of problems
depending how soft, and I think also KH readings.
Dan, can you give us the size of the tank, numbers & sizes of the bows in the
tank (as well as other biological loads), and frequency and % amount of water
changes? Do you feed once or twice a day, do you feed alot of food? And most
important, what is the GH and KH of your tap water? If you don't have a kit,
purchase the Tetra dual kit for ~ $10, about the price of a single bow. Also
what is the pH of your tank?
Suggestions to cool the fish down (mid 70's is on the right track) and massive
water changes will help. Once you know your exact KH try and move your
carbonate hardness, KH up to 6 degrees (that's 108 ppm). Use baking soda, it's
cheap and easy to dissolve in hot water for mixing. Move it some 2 degrees per
day so you don't shock the fish. My measurements show 1 teaspoon (3.64 grams
actual weight) {or 5 cc dry measurement} in 20 gallons of water will raise the
KH up 2 degrees, which is 36 ppm. Keep up the water changes and make sure that
you add back the baking soda that you remove with the water change. good luck.
Gary Lange
gwlange at STLNET.com
Rainbowfish Study Group of North America
http://home.stlnet.com/~gwlange/rainbowfish.index.html
> Another commonly touted causative organism is Aeromonas and there are more
> than one of them too.
>
> Cheers
>
> Bruce