Soil looks like one of the industry standards, akadama clay. No need to repot by the looks of it.

Honestly, Leatherback, it looks to me more like standard organic soil (normally poor draining…) just covered with a top layer of akadama.

I've found this to be a "normal" practice by some bonsai dealers...

If it is like this, I'd repot in pure akadama… much better draining and better watering control (though it needs higher frequency as it dries faster in summer).

That looks like some kind of volcanic grit on top of pure orgaic soil. Funny, I havent seen that before. Like descuise bad quality soil with a layer of good quality soil. Looks more professional.

I would repot in early spring. You can reuse the grit when repotting. Taking help from someone experienced in your area first time repotting is a good idea.

Maybe Sara can confirm whether

-

• it is only the area nearest to the trunk that stil holds regular soil
• or whether the whole pot is filled with it, only to be covered with a thin layer of akadama.

I must admit, I was under the assumption the first would be the case, considering

I bought my bonsai from a bonsai nursery

But true, maybe not all bonsai nurseries do proper rootwork.

I see there are different opinions and it is probably because I didn't take a good picture of it.
I will move more rocks and take a better photo

Here are some more pics of the soil. I hope it gives a better idea of its condition

So yes, it's definitely organic soil covered with a thin layer of akadama.

I would repot in early spring in full akadama.

thank you!! Will do