Shiseru's gill/flare flap is out, panting moderatley.

[Hershey]

I can't take pictures, but the left side of his gill/flare flap is out and the right side is okay. I put in the new heater with a WC yesterday and he seems better, but it's still out.

Housing
What size is your tank?-Divided 5
What temperature is your tank?-80-82
Does your tank have a filter?-Yes
Does your tank have an air stone or other type of aeration?-no
Is your tank heated?-Yes
What tank mates does your betta fish live with?-N/A

Food
What type of food do you feed your betta fish?-Omega one betta buffet pellets
How often do you feed your betta fish?-2x a day, 2 in the morning, 2 before I sleep.

Maintenance
How often do you perform a water change?-3 days to weekly.
What percentage of the water do you change when you perform a water change?-75-85%
What type of additives do you add to the water when you perform a water change?-Water conditioner, stress coat.

Water Parameters:
Have you tested your water? If so, what are the following parameters?
Not yet. It's late, so i'll tell results tomorrow. Changed water on 1-28-13.
Ammonia:
Nitrite:
Nitrate:
pH:
Hardness:
Alkalinity:

Symptoms and Treatment
How has your betta fish's appearance changed?-His anal fin is chomped a bit.
How has your betta fish's behavior changed?-Not much, still greets me, poops, is a big eater.
When did you start noticing the symptoms?-A few weeks ago
Have you started treating your fish? If so, how?-N/A, Clean water
Does your fish have any history of being ill?-He was fine in the cup I got him in.
How old is your fish (approximately)?-Adult, unsure of year.

[callistra]

I'm confused.. you said it's a divided 5 gallon but there are no other fish.. Nothing is on the other size? So your fish has 2.5g?

How long has this tank been set up?

This can be caused by injury or ammonia/nitrite poisoning

[Hershey]

Yes. Descole had just passed away and I didn't remove the divider.

Nov. 30th 2012, but the tank is uncycled.

[callistra]

If the tank is not cycled then you should be testing daily and doing a 50% change any time you see whether ammonia or nitrite show up on your testing kit.. no more than .25ppm. In addition to this a weekly 50% change with siphon is required. If you're going 3 days to a week before you do a water change on an uncycled tank you can very easily cause ammonia and nor nitrite poisoning, which is what he seems to have.

Also do you know what your other betta died from?

At this point he is not well enough to be used for cycling a tank. He needs to be QTed and treated with much more frequent water changes (depending on the size of the QT) and epsom salt at 1 tsp per gallon. It needs to be 100% pure magnesium sulfate with no other additives and it should be predissolved and added slowly over an hour to avoid shock.

[Hershey]

Okay. He'll be in a 1 gallon, so I'm guessing i'll have to do 100% changes every other day?

No. I do know there was a large amount on lint on his side of the tank, as much as I cleaned with the vac.
How long Should I treat him for?

[callistra]

Lint? I'm not sure what you mean..

At least a week, maybe two.. until he starts acting normal.