Hi again Carrot,
If its come from Dallas Bonsai, then I'm sure its perfectly suitable
.
In there you have lots of inorganics in the form of river sand and calcified clay to maintain soil structure and some organics to retain moisture and also provide a natural source of nitrogen. The screening removes the fine particles that reduce airspace and retain too much moisture around the roots. Once repotted, your tree will thank you for it.
One thing I have noticed with my trees is the more airflow given to the roots, the better the top growth. To give you a first hand example....
I have about 50 Scots pine seedlings which I decided to experiment with. Roughly 1/3 are in 100% organics, 1/3 in a mixture of about 70% inorganics/30% organic and the remainder in 100% inorganic. All mixtures were screened thoroughly to remove the fine particles.
Without getting a tape measure out, I'd say that those in the organic mixture are about 3" tall. Those in the 70/30 mixture approximately 5" and those in completely inorganic roughly 6-7".
All seedlings were germinated at the same time from the same batch of seed, fed and watered together and are situated next to one another, receiving equal sunlight. This goes to show how important drainage and airflow are in achieving good healthy growth in a tree. We are always concerned with how much we water and feed our trees, but all too often "airing" them is over looked.
I'll stop waffeling now.... but yes, the soil will be perfectly fine
All the best,
Aaron