Bronze Cory laying eggs

My big Bronze Cory was laying eggs most of the day yesterday. I took some
pictures of the eggs and of her with an egg sac. We have three other small
Bronze Corys which were with her all time, would they have fertilised the
eggs? Also, most of the eggs have been eaten by the Clown Loaches although
there are still some in the top left hand corner of the tank and on the back
glass, in the middle, near the water line. The thing is, if the eggs are
still there, what should do about a 20% water change due this weekend.
Removing this amount of water will take the eggs above the water line.

Thanks for your advice. You helped me out a while ago when I had problems
with the tank so I'm sure you will be a great help again.

Ruth