I have a 55 gallon tank that right now houses my fire eel, 6 discus, and 3 clown loaches . . .It also had a really bad algae problem, so I took out the carbon in the filter and put in some algae killing chemicals. Ever since then, the fire eel has been going down hill. The discus and the clown loaches are totally fine . . .not showing signs of stress or anything . . .but the fire eel is not coming out of hiding rock to eat, and has labored breathing. I put the carbon back in the filter, and did a 1/3 water change . . .is there anything else I can do to try to coax the guy back to health?