Goldfish-Bacterial fin rot- Help!

[Labyrinth]

Okay, first of all, I'm new here, and I admit that I joined just so I can ask this question, BUT, I am really enjoying my new aquarium hobby thing, so I'll probably become pretty active here if all works out.

Okay, so I have these two goldfish. I won them at a carnival on March 30, where they were being kept in very poor conditions (in tiny plastic cups for the three days of the fair, out in the hot sun) so I guess I was kind of wanting to "rescue" them in way? Anyway, they are both very small, the smaller one is about an inch in length and the bigger on is about an inch and a half. The smaller one also had a big dark spot covering its head and part of its back. I at first kept them in a one gallon plastic aquarium, without a filter for the first week because it was all had. Then I went to the pet store to get a bigger aquarium (2.5 gallon I believe) and a bubblestone because I was afraid they weren't getting enough air and a bottle of stresscoat (which the pet store guy recommended to me to get rid of chlorine). (I dont have much money so I've had to get supplies gradually, which is bad, I know...) I asked the guy at the pet store about the dark spot and he told me it was nothing because diseases are usually white. So I moved them into the new aquarium and since I was at university at the time, I only had chlorinated water. I would fill a separate container with the water and add a few drops of the stresscoat and leave it for 24 hours before using to change a portion of the water everytime it started to look not so clear, because I did not have a filter yet. After a while I noticed that the dark spot on the small fish was getting darker and his tailfins were starting to look ragged. I didnt know what it was so I didnt do anything. A few days later the tail fins were getting worse and the bigger fish was starting to have ragged tail fins as well. So I researched and assumed it was fin rot, though everywhere I look, says to find a different treatment, none of which I had access to at the time. So I took the fish home and bought them a filter and changed all the water and cleaned the tank completely and then returned them to the tank. Also, I have well water at home so there is no chlorine, but I'm unsure about the effects of the minerals and such in well water on the fish, so I have continued to add the stresscoat to the water. Then I had to go back to school for finals, and couldn't take them with me because of space issues with moving out and such. Since there was nothing else I could do at the time, I made sure there water was clean and then left them in the care of my mom who would sprinkle food in every now and then, she wasnt too willing to do anything else. I came home two weeks later, (May 13) and the big fish seems completely cured. It's fins seem to have completely grown back! But the smaller fish has only gotten so much worse! Its tail fin is completely gone and the dark spot is completely black and has extended across its back, and covered the fin on its back, which is almost completely gone as well. The small fish also cant swim well now, and usually stays completly vertical with its nose towards the bottom of the tank. It can swim by wiggling its whole body and can become horizontal again after gaining speed. It still seems active for the most part, though not as lively as the big fish and it still eats as much as ever (as far as I have noticed). About an hour ago I moved it into the small one gallon tank that I still have to quarantine it from the bigger fish who seems to be healing nicely.
My Questions:
I've read that I should add antibiotics to the water, what kind and how much are they?
I also read that I should add salt to the water, is that true or will it hurt my fish? (I dont have any non-iodized salt anyway, I would have to buy some tomorrow)
Is there anything I could now to help?
Is my fish gonna die?
Should I do something to treat the bigger now seemingly healthy fish as well?
What is the black spot all about?
Is well water okay for fish?
Any other information would help as well. I really really like my fish and I want them to be healthy again.

Thank you for your help, and I'm sorry this is so long!

[Lady Hobbs]

Fin rot is a bacterial infection and will continue to eat away at this fish until it eats into the body. If this fish is as bad off as it sounds, you probably need to part ways with it. Water changes need to be done on a regular basis and I assume with you gone this hasn't happened.

Your tank is too small for two goldfish anyway. Sorry to be the bearer of bad news.

[cocoa_pleco]

sorry to hear that. goldfish need 20g for the first, and 10g thereafter. The best thing for fin rot is lots of water changes. Clean water means the bacteria cant survive on the fishes fins

[Lady Hobbs]

Totally agree!!!! 2.5 gallon is a betta tank or possibly for neon's. Way too small for even one goldfish.

[cocoa_pleco]

Ive heard of 2.5g's having-

1 betta
or
5 neons
or
3 killis
or
5 ghost shrimp

[Mr. Koi]

is this a result of fin rot on my bala shark?? im concerned...

or is it that the other goldfishes are biting his fins? if you didnt notice in the pics...the dorsal and fintail are what seems to be bloodshot ...is that the case?? im really concerned...thats my FAVORITE fish! :((

[Juannie]

Well I've been fighting finrot/fungus on my black moor for nearly 6months now, he's been getting it on and off when we've had massive heat changes here. I added epsom salts to help them with the slime of coat on their bodies and also any fluid build up (just in case), I've also used Pimafix & Melafix together, these have both worked along with water changes but when they haven't worked I've actually used medication and that helped. I do know that when they're healing from fin rot my fish had black smudges on them and that is (from what I've read) burn or proof that they're healing - well in their case it seems true: http://www.petlibrary.com/goldfish/smudge.htm, another reason is ammonia burn.

As for the shark, if he hasn't been bitten I do get blood marks in the tails of my goldfish on the rare occasion but once I've done a water change this usually clears up quickly - water changes are the key!

[cocoa_pleco]

goldfish are strictly for species only tanks except with loaches and white clouds, which are coldwater. Bala's need 80f, and goldies need 65F. If the tank is warm, the goldfish will die early, and if its cold the tropical fish will die early.

Its not the balas. Theyre peaceful and tend to themselves. I have 4 temporarily in a 30g hex with 2 platy's and a large angel and 5 green corys and they all mind their own business

[bscman]

is this a result of fin rot on my bala shark?? im concerned...

or is it that the other goldfishes are biting his fins? if you didnt notice in the pics...the dorsal and fintail are what seems to be bloodshot ...is that the case?? im really concerned...thats my FAVORITE fish! :((

How big is that tank?
Judging from the pic, it looks AWEFULLY SMALL...

And with the fish that show in the picture, it should probably be over 100gallons given the nature/size of those fish when fully grown.
Not to mention goldfish and bala's should NOT be kept in the same tank...one is tropical, the other coldwater.

What temp are you keeping it at?
Tropical fish in cold waters are magnets for disease.

[cocoa_pleco]

yeah, that tank looks pretty packed. like bscman said, a 100g would work, but i personally say since goldfish are pigs a 150G with one of those huge RENA XP4 filter would be adequate.