I added some tank mates and since then the perch seem to have grown a small bit and show more vivid coloration. They're finally 2" (by measurement) and living peacefully with 6 Blacknose Dace and 5 Johhny Darters. The dace are going into a different 20 high once I turn it into a riffle tank and after the perch growout this tank I'm making it a Swamp Biotope for the Johnnys and maybe some Killies as well.
I think I'm about to lose one of the two that are left, it keeps swimming up the side of the tank vertically and won't eat, I think it's a swim bladed issue. The other one won't eat either so it may not be long before they're all gone. This sucks.
Sorry for your loss. I had one from about the size you got yours. It passed at about 12". Got it eating freeze dried krill and floating pellets and the occasional feeders.