Why do Iridescent Sharks always keep l*****g the Aquarium sides?

Question

I have 2 Iridescent Sharks ( Pangassius hypopthalmus ) in my fish tank and what I observe is that they always keep l*****g the sides of the glass tank.Why is that so?

Answer 1

It could be one of two reasons. One because they are l*****g the small amount of algae that is on the glass or two because they need some fresh water aquarium salt. You can get this anywhere like a petstore or walmart. Try the aquarium salt and see how it goes.