Please help!!

[mnat7954]

Hey guys,
What is this???
I recently added 6 new fish and now all my 5 old fish look like this!! It's been almost a week now and they don't seem to be getting better BUT they are all still eating!
I have raised the temperature to 31 degrees and am using Bactonex and Tri Sulfa on the advice of an aquarium.
Is this bacterial or fungal? Is there anything else I can do to help? I don't want them to die!!