White powdery substances on the leaves

[Firstbonsai124]

Hey!
I’ve been noticing that my leaves are starting to get this white substances on them. It starts off from the edge and moves inward. I can wipe the off with my fingers but it will come up again later. Does anyone have an experience similar to this?
I am new to taking care of my bonsai and it has only been 2 weeks since I bought it. Help is greatly appreciated. Thank you!

 

[Wires_Guy_wires]

Do you spray them with water?
Could be just regular garden center dust. Give them a good shower and it'll probably never come back.

 

[Shibui]

I can only make out one tiny white dot on those photos. That could be the quality of the photo or just my old eyes.
There are a number of things that could be white substance on leave of figs.
Dust a s mentioned
Calcium deposits left as water evaporates from the leaves - just water the soil rather than spraying the leaves.
Powdery mildew (not sure if that affects ficus?) Fungal disease caused by humidity. Usually not too much of a problem. Avoid spraying the leaves, treat with a suitable fungicide if it gets worse.
Scale or woolly aphid. Both are different insects that suck on the plant's sap. They can be quite small but can be squashed and have pinkish body fluids. Wipe off by hand or wipe with alcohol or treat the tree with an insecticide.

It is good that you are paying such close attention. Certainly does not look like a problem for your fig yet.
Please find out how to care for indoor ficus bonsai properly. Your tree looks good so far but we get so many posts after the tree is dying because the owner does not know.

 

[Wires_Guy_wires]

I don't think tropical species are ever bothered by mildew @Shibui . At least, I've never heard about it and since their natural range is tropical, the environment is optimal for mildew to thrive.
I'm seeing something like clay powder deposits. Cheap lemon and mandarin trees around here have it due them being shipped in stacks. The fine dry powder ends up all over the plants, then it dissolves in water and when the water evaporates, it forms a layer on the foliage where the droplets used to hang. That seems to be the case here too; always on the bottom half.
No need for fungicides or alcohol, a good old water shower should suffice.

 

[shinmai]

Welcome to the neighborhood!
First things first--put your location and USDA zone on your avatar--it helps us to answer questions in the context of the environment where a poster lives.
That sure looks to me like a water-related deposit. As suggested, I would give the leaves a washing with water, and then dab away any droplets with a paper towel. Then from now on water the soil, keeping it off the leaves. If it doesn't reappear, that was your problem. I doubt that it's fungal in nature, because most fungal problems in ficus are root-related, with symptoms including yellowing leaves that drop, and desiccated fine branches, neither of those being visible here.
In summer especially, if you get water droplets on the leaves, they can act like a magnifying glass, causing sunlight to burn the leaves.
FWIW, a couple that I had taught in a beginner class called me in a panic, because both of their ficus that they got from the class had a similar deposit on the leaves. They thought it might be powdery mildew. When they sent me pictures, it looked a lot like yours, and washing the leaves with water was all it took. In their case, their water was very hard. I don't know about yours.
Best of luck and enjoy your tree.