E_americanus;4032933; said:given that most of those tankmates are not recommended for gars, one cannot discount the possibility that one of them or more has stressed out the gar in some way. this could lead to sloughing of slime coat and potential bacterial infection.
i would set up a hospital tank, even if it's just a tub with a heater and sponge filter or airstone. set the temp back up to 82F and add 1 tbsp of salt per 10 gallons of water. i would do a water change of at least 50% each day until the condition starts to improve.
what is your temp currently? normally a gar shouldn't react like this to the temp change, so we can likely rule that out. if none of the other fishes are showing similar signs, it further suggests that removing the gar and treating it on its own may be the best course of action.
i would move on this sooner than later because slime coat bacterial infections are usually quite aggressive with gars, and cannot be treated once they reach a certain stage. if you bump the temp/water changes/add salt the fish should likely recover--
--solomon
The fish is has been solo in the tank for sometime now but I will take on your suggestion about bumping up the temp and keeping up the WC and salt treatment.
Thanks for your advice.
