White mould on ficus soil - how to get rid?

[Storm_Lord]

Hi everyone! A couple of months ago, I posted about my Ficus dropping leaves, and you all gave some excellent advice. I repotted the tree, as suggested, and it seems to be good and healthy again. Thanks!

One problem, though: over the past couple of days, a whitish mould has appeared on the soil. After doing some research, I was thinking of brushing the mould away, then applying some cinnamon. But I wanted to consult you guys first. A) is this mould a problem and B) how would you recommend resolving it?

 

[Shibui]

Are you certain that is mould?
Mineral deposits are a common feature when potted plants don't get a regular flush with lots of water.
Every day water evaporates from the soil surface leaving behind any minerals that were in the water. After a few weeks/months there can be enough minerals to form a white crust on the soil and or trunk and or pot. Usually happens faster in summer when evaporation is greater and where water has lots of mineral content. Fertilizer can also contribute to mineral crust as fert contains minerals.

If it is mould it should disappear when the soil surface gets dry. Fungicide would also be effective but I don't think that's necessary as most moulds are harmless to the trees.