personally I wouldn't cover it like that, even though it kinda is a great idea. hehe.. anyways the mother really needs to fan the egg to keep fungi from growing on it and killing the poor little babies.. Id probably just get a tank divider, that's what i'm currently using in my 55g tank with my bolivian rams ( Im a new proud dad myself
) It keeps my two angelsfish away along with my tetras. The only thing on there side right now is two otos.. Which the parent will not let them come close to the little free swimmers right now.
I dont know if panda cory could eat its eggs or not. Hopefully someone else can answer that one. I know it takes a few times for some fish to become good parents..
heres a little info I found for you:
Egg and fry development
The eggs will hatch after 4-5 days if the water temperature is around 25ļC. At this point, the fry is no bigger than 6 mm and will seek out a sheltered place where they can stay until they grow bigger. It can take several weeks before they feel confident enough to swim around freely in the aquarium even if they have their own aquarium without any adult fish. Hints of the attractive panda pattern can be seen when they are no older than two weeks. After four weeks, they will be over 1 cm long and much thicker than when they hatched. At two months of age, Corydoras panda
fry are normally at least 2 cm long.
When the fry hatch, they will feed from their yolk sac for another 48 hours. Feeding is therefore unnecessary during the first two days. Microworms is a good first food for Corydoras panda
fry. As they grow larger, you can start giving them newly hatched brine shrimp and then gradually increase the size of the brine shrimps.