You said the magic word. Charcoal has to be removed from the tank when you medicate fish. So if you are talking about the tank where Yoshi is in please remove the charcoal from his tank completely now and keep it out until he is not being medicated anymore. IF the filter media is not able to be seperated from the charcoal then what you do is break the chamber that holds the charcoal and get it dumped out and then replace the rest of the media in the filter. If you are not talking about the tank that Yoshi is in then disregard.

When he is not on the medication any longer the charcoal can be put back to REMOVE the meds from the tank..this is one thing it does really well. It is one of its main purposes, removing medication.

Rose