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?