In the "help please: thread, Eric Schreiber wrote:
- Maybe add salt (unless you have lots of live plants, scaleless fish,
cordydoras, or tetras, none of which like salt). No more than 1/2
tablespoon per gallon.

Forget the bit about scaleless fish.

My West Australian freshwater Cobblers (Tandanus bostocki) are scaleless.
They are very sensitive to fungal infections, particularly White Spot.
Because of the lack of scales, the White Spot looks more like White Blob.

By keeping a small amount of salt in the water, I keep the fungus at bay.

Jim