When Your fish are not looking so well, here are some basic things you should do.
1. You should clean the fish tank-
~Use a scrubber to clean off the walls of the aquarium
2. You should do a water change-
~ at the most I would say 25%
3. Clean your gravel-
~With a siphen hose
~Again only 25% of the water should b removed.
Optionals-
~Raise the tempeature between 3 and 5 degrees. You should only have to be at 80 degrees, nothing more until it will start getting a little risky.
~Add aquarium salt(the box the salt comes in should tell how much salt to put in.