Panda corydoras need a deliberate bottom feed once or twice a day, not whatever scraps drift down from feeding the rest of the tank. These small, black-and-cream catfish spend their lives nosing through the top layer of substrate for worms and tiny crustaceans, and their mouths point down for exactly that work. A panda cannot chase flakes in midwater, so a tank fed only from the surface can starve a group of them slowly while the water tests fine and the other fish thrive.
A feeding pattern built around the substrate
The most reliable pattern is one targeted sinking feed a day, plus a second smaller one in a busy community tank where competition is fierce. Drop a small sinking pellet or a fragment of bottom-feeder wafer per fish onto open sand where the group likes to rest, and let them find it by scent and barbel. Many keepers make the main cory feed the evening one, lights still on but the day winding down, because panda corydoras grow noticeably bolder as dusk approaches and will forage in the open instead of darting between plant bases.
Using a feeding dish or a cleared patch of sand keeps soft foods out of the gravel, where pandas cannot dig them free and they only foul the bed.
What to put in front of them
Panda corydoras are insectivores at heart. Sinking micro pellets and crushed wafers made for bottom feeders make a sound daily base, but the foods that trigger real group foraging are thawed daphnia, baby brine shrimp, grindal-style worms, and finely crumbled bloodworm that settle onto the sand. Rest a turkey baster's worth of thawed food gently on the substrate in the pandas' corner rather than squirting it into the current, where tetras will intercept almost all of it.
Avoid the common mistake of buying a large algae wafer and assuming the pandas are covered. They will graze one, but algae is not the core of this species' diet, and a group fed mostly on it tends to look thin and faded despite always having food in the tank.
Checking that small fish are getting enough
Pandas are group fish, and the group is your gauge. After feeding, bellies viewed from above should look softly rounded, and the whole shoal should work the sand together, barbels flicking. A panda that stays tucked under a leaf while the others feed, or one whose back looks sharp and pinched behind the head, is missing out; feed that corner directly and watch it eat. Persistent thinness in several fish, damaged or shortening barbels, or pandas sitting listless on the bottom are signs to look beyond the menu, and an aquatic veterinarian is the right call if appetite drops away too.
Keep the substrate itself part of the routine. Panda barbels are delicate, so food buried in sharp, dirty gravel both disappears and harms them; a light vacuum of the feeding patch during water changes keeps their dining area clean.
Not letting the bottom feed get forgotten
In many tanks the surface fish get fed religiously while the corydoras' own meal is the one that slips, precisely because it happens separately. Scheduling it as its own job fixes that. KinsLe's Care Teams lets you assign the panda corydoras' sinking feed to whoever is on tank duty and record its completion time, so this quiet little species gets its meal by design rather than by leftover.