Re: Mold? Fungus? Pictures!
The stuff on the left is fungus. Some sort of basidiomycete. Those are the wood rotters and you have a ton of dead wood in that soil. It presents no problem to your live plants. Scooping it out with a spoon works just fine but you'll never get rid of it completley as long as you have all that dead wood in there. You could just switch the soil you use if the scooping becomes to big of a pain. The stuff on the right doesn't look like mites to me. Usually mites will hang out along the mid-rib and the viens. This stuff is distinctly inter-vienal. Also, you can see nearly identical symptoms along the edges and tips of most of the leaves on that one branch progressing inward. The unifiormity of the symptoms suggest a nutrient deficiancy or water deficiency (my money is on water) because, unlike a pest or disease, a lack of something that the plant needs often hits the entire plant in the same way at the same time. But, it is just that one branch. That has me thinking that something is blocking the vascular tissue there. So, even though you water it and put nutrients in the soil for it, that stuff just doesn't get transported like it should. I would bet that if you cut off the unhealthy branch and looked at the xylem / phloem in cross-section, you would find browning or yellowing. At that point, to get a working I.D. on what the problem is you would have do a litte research on which vascular diseases (fungal or bacterial) attack that species of plant. Then you figure out which ones are present in your part of the world. Then you would have a pretty good idea of what the problem is. To get an actual positive I.D. you would have to culture out the pathogen and I.D. fruiting bodies or spores if fungal, or bacterial spores. (diseases are just a pain like that).