Help! my catfish's gill is stuck shut

[k2snowboards88]

I don't know what to do. I had an amonia spike and my catfish got sick. one of them died the same day and the other has a white spot on his fin. He's survived 4 days since the first one died. but i woke up today and amonia and nitrite levels are pretty much 0. But the white spot is still on the catfish's fin and his right gill is closed shut. Is there anything i can/should do?

 

[Cheese Specialist]

How are the other fish? What kind of catfish is it? Do 30% waterchanges daily until amonia and nitrite levels are at 0.

 

[k2snowboards88]

I'm pretty sure all of them have ich now. The catfish is dead. The tiger barbs like rubbing their bellies against rocks and plants and have black spots on them. The red fin shark chases everything that gets too close and is a lighter color than usual. The eel has some red spots.