I have a Whitecloud that hasn't wanted to eat since I got him in May, he's stayed tiny and is now emaciated. One other like him (out of ten) has already passed. I also have 1 Kyathit Danio that's extremely emaciated with a second (out of ten) starting to look skinny.
The rest of the tank is plump and boisterous, I've been overfeeding. I use location, different foods, and timing to make sure food is available to everyone. I've watched the emaciated fish ignore food repeatedly, often spitting out anything they do start to eat. Flake, pellet, wafer, dried, and frozen food all get ignored. All of it is from Aquarium Co-Op thus quality.
I don't see any external signs of parasites, injury, or other distress. Weekly water changes, all parameters good, heavily planted high-tech tank.
Any ideas on what I can do differently?
Thank you!