Q About Fin Rot

[yashinfan]

When I bought my two female swordtails from PetSmart, they came with a little bit of fin rot. I thought, what the hey, I'll quarantine them and medicate them and they'll be fine. So I put them in a 5 gallon, used a lil bit of sea salt, fungus eliminator and did lots of water changes. One got a lot better and the other stayed the same. I started to use Melafix as well, and eventually one was getting really fat with babies so I decided I would remove the other female.
So then there was one female with the bad finrot in a 4.5 gallon, and the pregnant one in the 5 gallon. I kept treating her and eventually she had her babies and I removed her. She looked fine so she now resides in the 30 gallon.
As for the 4.5 gallon sword, she will not get better! It's not getting any worse but Melafix, Fungus Eliminator and Salt have not worked. Now I've resorted to twice a week water changes and melafix only.
So I was wondering: Does she have finrot that can be cured? Will the fin rot spread to other fish if I move her into another tank? Is her fin rot benign maybe, in that it is there but it's not going to do any further damage?
It's been at least 2-3 weeks since I started medicating. I bought them back in September.

[kveeti]

The fit rot could be bacterial and not fungal, in which case you should probably switch medicines.

Here is just one site, with good concise reading under "Fungal Infections" and "Bacterial Infections".

http://www.efishtank.com/Disease&tx.htm

[swany]

The same thing happend to me and I wound up using the Aquatronics brand antibiotics. I can't remember the name but the one with nitrofurazone alone did not touch it, but the one with both nitrofurazone and another antibiotic in it (that name escapes me too) did the trick.

Good luck.
Swany

[yashinfan]

I also wonder if this would make it worse:
Yesterday I stuck a thermometre in the 4.5 gallon tank and the temp was about 28 C instead of 24! I did a water change and lowered the heater to not heat the water above 24. So I was thinking, that on top of having fin rot, she was being stressed with abnormally high temperatures. Do you think this is why the fin rot would not go away? According to the site you gave me, it sounds bacterial. But when I looked at her today, she seemed to be doing better with the temp down @ 24C.