These fish look very healthy and happy. For small discus, I'd recommend you wipe the bottom and sides of the tank every so often to reduce the slime buildup. You'll need to keep up the big water changes for these fish to round up, and they will if they're raised in clean water. You'll need to keep that up until they get to ~5" at least, so even after they go into a 75 gal tank.
Good luck, Willie