Hummm........this should not be a problem because anything other than sand or fine gravel is a very unsuitable substrate for corys. In the long run such substrate is likely to damage their delicate barbels and result in their deaths.HeatherSweetness said:...algae wafers can get messy if you have larger rocks for a substrate,pellets too.
Hey I have three cory cats, I feed them Nutrafin Max sinkin tabs but they make a mess.
If you are using pebbles or rocks that they cannot easily push aside, please either change it to something more appropriate or remove the corys from that tank.