really sick betta

Question
Hi, thanks for reading this.

I have a Beta fish here who is very sick and i need to know what i can do to help him. he is normally a rather gorgeous blue-indigo fish who though sometimes lethargic, acted normally. his tank was unfortunately left in a rather filthy state for over a month. this has immediately been fixed and he has been moved to a clean container (not the tank) with a small amount of salt added. I plan to keep switching containers every 3 days or less to ensure a clean enviroment. the tank he is in normally is approx. 8L.

His symptoms are, inflamed gills, advanced fin and scale rot, raised scales, lethargy, loss of colour, and loss of appitite.His weight however is actually pretty normal just a tad under weight. I know that many of these symptoms, especially when experienced together, are known to be deadly. I am hoping however that there is at least a small chance to save Fae (the fish).

If you could please tell me what steps and medications to use to help him, or if it is too late to do so I would be very grateful.

Thank you,
K

Answer
Hi K,
A betta should be kept in a heated 5 gallon tank.  Keeping bettas in small containers is not the right way to keep them.  They are tropical fish, and should be in a 80-82 degree tank which must be heated with a thermostat.  When heating a tank for a Betta, or any other fish, this must be done slowly.  One degree every 2 days.  Bettas kept in small tanks, containers, vases, etc. and cool water will get sick.  Tropical fish are cold under this temperature.
The fact that her water was not changed, and she is now sick, you will have to treat her with an antibiotic.  Tetracycline would be my choice, along with diluted aquarium salt.  (1 teaspoon to 5 gallons of water)  Follow the instructions on the package, and be careful not to overdose.  Change all of her water every three days, and continue treatment.  Fae should recover in clean water, and antibiotics.  I hope she makes it.
Lynda