Bought 10 panda corydoras and have lost 5 in two weeks

[HicksFam]

We have a 55 gallon tank and within two weeks of buying our panda cories we lost have of them. We also have platies that seem to be pretty aggressively eating food that falls to the bottom. Water tests seem okay. Temperature is at around 76 for the tank and we were told that should be okay. All survivors are a little larger. We are trying to decide if we should get more or if they are not going to be hardy enough for our tank. Started researching how to feed them so their food gets past the platies too. Any thoughts?

[Aiken Drum]

Corys are naturally nocturnal feeders, although my pandas will feed whenever food is present. They are pretty good at finding food. If you are worried about them not getting enough food try feeding them just before you turn off the lights.

Also, lets rule out any other causes of stress.

What are your water parameters? pH, ammonia, nitrite, nitrate?

Are there any signs of distress or illness? Are their barbels looking good?

Can you give some other details about your tank?Filter? Whats your substrate? Plants? In your other posts you have mentioned fish other than those mentioned in this post. What is your stocking?