Betta looks sick in new home

[WDW Donna]

And I don't mean sick in the cool way the kids use nowadays! My daughter brought home this poor female with bad fin rot and kept her
in a half gal bowl for the last 2-3 weeks. No heater, no filter, just water
changes and meds for the fin rot.
Well she was looking so much better!! Her demeaner was always good she
just had tattered fins. We put her in her new 1.5gal, heated, decorated, filtered home two days ago and she has gone downhill! she is sitting on the bottom and her fins seem to be clamped. I was afraid of dropsy so I am using aquarium salt and melafix. I don't want to put her back into the bowl since it is not heated and don't want to disrupt her again. (We did a 50% clean on my daughters 5gal tank the same day using the same water and water conditioner and that betta is fine. )

Housing
What size is your tank? 2.5gal
What temperature is your tank? 80
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? none

Food
What type of food do you feed your betta fish? aqueon betta pellets
How often do you feed your betta fish? 2pellets morning, 2 at night

Maintenance
How often do you perform a water change?haven't yet, new tank
What percentage of the water do you change when you perform a water change?
What type of additives do you add to the water when you perform a water change?Prime water conditioner

Water Parameters:
Have you tested your water? If so, what are the following parameters?

Ammonia:1.0 (only test kit I have at the moment)
Nitrite:
Nitrate:
pH:
Hardness:
Alkalinity:

Symptoms and Treatment
How has your betta fish's appearance changed?fins seem clamped
How has your betta fish's behavior changed?sitting on bottom alot. Will come up and swim around a little, won't eat, swims up to top and takes a gulp of air then back down
When did you start noticing the symptoms?two days ago
Have you started treating your fish? If so, how? aquarium salt and Melafix
Does your fish have any history of being ill? had fin rot when my daughter brought her home from Petsmart. She felt bad and wanted to try and help her. She has another betta so she is not new to these fish.
How old is your fish (approximately)? No idea. a few months I guess.

[lvandert]

ok first off the melafix is a no-no. It does more harm than good for these guys. the aq salt was a good move though. I would get some stress coat for her as well. You should be doing 100% water changes every other day with a 1.5 gal, especially if she's sick. If you want to get medication go with a general cure all. it should say on there that it will heal finrot.