wrote:
I have lurked this group for a while, and learned a lot from many
people. I just wanted to introduce myself and hopefully get some
feedback on my setup.

First off, the setup: I have one large comet that I've kept for 8
years. He started at about an inch and is now over 7 inches. (I think
he's a he because of a pretty thick leading edge on the anal fin, but I
haven't known enough fish to compare.) He's currently in 29 gallons
with an Emperor 280 and 18 inch bubble wall. I use the standard
cartridge in the filter, plus activated charcoal in the media catridge,
cause he's a big dirty fish. He eats TetraFin flakes and ocassional
frozen brine shrimp and rejects most everything else.

He is generally healthy, and very alert to human interaction, but very
active and aggressive and beat himself up on a composite rock formation
that I tried a few months ago. He lost a bunch of scales and I think
he may have started to develop an infection, so I changed the setup to
soft and smooth and treated with medicated food; all seemed well.

Chemistries are generally ideal. Ph is 7.5-7.6, Ammonia is 0, Nitrite
is 0, Nitrate is 40 ppm.

Second, the issue: ragged fins. I noticed a bit of raggedness on the
edges of his fins. No major splits or missing chunks yet, but some
very small black marks along the edges in a few places. I know ragged
fins usually means fin/tail rot, but I wasn't sure if the black marks
were consistent with this. I had thought the black might have been
ammonia burns.

I changed out all the filtration media, did a 50% change and about a
half cup of salt. I'm holding off on the treatment to see if that does
anything (water quality probs instead of infection). If it's an
infection, I'm also not really sure what treatment to use. According
to the Mardel literature, fin rot can be caused by gram-postive or
gram-negative infection. So...

Sorry about the long post, but if anyone has thoughts or advice please
let me know thanks.

JRF

I agree that salt and water quality improvements are the way to go. I'd
start with 25% weekly water changes. Your 40 ppm nitrate suggests that
you're not changing enough. Also, I don't usually change out all of the
filtration media at once in a tank - you can reduce bacterial
populations enough to cause a mini cycle.

With finrot, actual infections usually look whitish at the edges of the
rotting fin, rather than just ragged. Ammonia burn is a reasonable
thing to suspect. Sometimes a very thorough gravel clean and a bit of
AmQuel for a couple of weeks while the bacteria regrow helps improve
tank conditions.

If you eventually want to go the medicine route, I have cured stubborn
bacterial finrot with Paragon 2 by Aquatronics. Paragon 2 contains
metronidazole, furazolidone, neomycin sulfate, and naladixic acid.
Unfortunately, it will kill your filter bacteria too so you usually have
to manage ammonia and recycle the tank. I only use it in a hospital.

Kanamycin and Maracyn 2 are more filter friendly, so you might try
either of those first. They don't kill all bacteria, but they do hit a
lot of the common ones.

--
Elaine T __
http://eethomp.com/fish.html '__
rec.aquaria.* FAQ http://faq.thekrib.com