can banded sharks get ich and wath is the symptoms?

Answer 1

The symptoms would be white spots that look like someone sprinkled the fish with salt.

Are what you have the Chinese hi-fin banded sharks? The reason I ask is that these are coldwater fish - one of the suggested treatments for ich is to turn up the water heater, but do this slowly so you don't severely stress these fish. If you decide to treat them at a lower temperature, you'll need to treat for a longer period to make sure you get it all. The normal treatment should be for 10-14 days or at least 3-5 days after you no longer see spots on the fish, but if you're treating at a lower temperature, I'd wait at least a week after.