He probably has an infection or may have the same fungus (just internally). You should probably treat the whole tank for that fungus, as she was probably infected in the main tank... as long as it is safe for your catfish.

Is the side that your male is attacking see through or do you have the paper decor around your tank? If it's see through, you should probably put some paper up on that side so he might stop.

How many times are you feeding your fish? Once a day is all that's necessary. When you're new to the hobby it seems like everything goes wrong, but you'll get the hang of it just stick with it.

How often are you doing water changes? And how much are you changing each time?
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Phishie
Site Coordinator

"An ounce of prevention is worth a pound of cure."