1) How often do you change their water?
2) Exactly how much Aquarium salt did you add?
3) What brand of water conditioner are you using?
The best way to treat fin rot is to keep them in clean, warm water. With a one gallon tank, this means doing 100% water changes every other day.
If you want to keep using the Aquarium salt, I would recommend using 1 teaspoon of Aquarium salt. Make sure it's completely dissolved. Do not use Aquarium salt for more than 10 days! Using it more than that can harm their internal organs.
Also, a lot of people recommend API Stress Coat water conditioner. It contains aloe, which can help promote healing. If you get the Stress Coat, use it in place of your regular water conditioner. (You don't need two types of conditioner.)
Always acclimate slowly, whenever you do a water change, or add something new (such as salt, etc), so they aren't shocked.
Last edited by LittleBlueFishlets; 02-09-2013 at 12:13 PM.