Is it possible for you to upload a photo here so that we can see what the problem looks like?
A photo of the entire plant and pot as well as a leaf, or whatever part of the plant is showing the "fungus", will help determine what the problem might be and then we can offer suggestions as to how to correct it. To upload a picture:
1. Click on the green area at bottom left of the page where it says Upload an Image.
2. Select a photo from your computer to open it and you will see movement as it's downloading and then you will notice symbols and letters that look something like the following: [lightbox]2018-05/debbekayd/1778b7[lightbox]
3. Click on the green area at bottom that says Finished and