I've looked at the leaves on the plant and can't find anything on them, both day and night. Thanks

surya55, I suggest that you obtain some "gnat cards" and place one or two in the container. They trap flying insects.
They are yellow (the color is attractive to insects, they say) and quite sticky. They certainly work for fungus gnats.
I really cannot say if fly paper or "Scotch" tape will work as well.

I've used those yellow plastic spoons and knives and coated them with vaseline,the knat/flies get on and can't get off ,it suffocates them.Cheap and easy.
kathi

I have had the same problem in middle Georgia and our local UGA Extension Officer told me that it was caused by a fungus or an emulsion that certain insects use to lay their eggs in. As the young ones hatch, they first survive on the nutritious emulsion from the mother insect but also gnaw on the chlorophyll of the leaves. I used a weak solution of Potassium permanganate and it worked wonders on prevailing spots and proved preventative as well.

This is an old discussions, but fungus gnats don't damage leaves. In the case of the above pic, unless more spots had shown up, whatever had a taste was probably already long gone.

Thanks Tiffany.

and nothing applied on the leaf.. did anything to change those spots ... i mean they would never heal.. if anyone is thinking that ...

ken