A couple of months ago, one of my discus stopped eating and stayed at the back of the tank. All other remain fine. I have taken him out and put him in a quarantine tank with same ph parameters (around 7.5). He still will not eat - not pellet, live worms, frozen worms or freeze dried worms. I have noticed that his faeces seem to be long, white and stringy. I have elevated the temperature in the tank to around 30 degrees and change 40% of the 100 litre tank every second day. He does not seem to be emaciated.

Given that it has been so long since he as eaten, I need to solve this problem sooner rather than later. Can somebody help with a diagnosis and perhaps a medication.

Thank you.

Steve Williams