Ok. Here I go again. I'm not having any luck using this forum. But, as I said, here I go. I have 2 discus that are emaciated. My tank is a 90 gallon and moderately planted; temperature is 86 degrees; I do 50% weekly water changes; PH 6.8-7.0; Nitrates and Nitrites 0; Hardness is around 30 ppm; Ammonia is 0; the tank has been up for 17 years; it has 2 Eheim filters together rated for 120 gallons; 13 watt sterlizer; plant food is the only chemical I use except for a dechlorinater at water changes; tank houses 7 discus, 23 rummynose tetras and 14 cardinal tetras; I feed, frozen bloodworms, live brine shrimp occasionally, high quality flake food, mysis shrimp, frozen beefheart. I have placed the 2 thin discus in a cycled 20 gallon hospital tank and tried 2 different times to treat with Praziquantel. Then I treated with Metronidazole for 10 days. To no avail. After a month, I treated with Kanamycin for 10 days. To no avail. I am totally stumped. They are still eating and fins are extended (no clamping) and look good. Their color is also good. I am praying that this message gets to someone and, if so, they can help me. If not, I guess I will just wait for them to die and hope none of the others get, whatever this is. PLEASE SOMEBODY HELP ME!!!