It depends. Two of the three ingredients should be in the 1/16 - 1/8" size range. If the third ingredient is a little larger, or a little smaller, it doesn't affect drainage or aeration to anywhere near the way it does if 2 of the three ingredients are OUTSIDE of that size range. So, if the bark and Turface are in the 1/16 - 1/8" size range, a larger grit component isn't too much of a problem, though it's still something less than ideal. If one of the other components is large as well, then you'll have an extremely well-aerated soil and may have difficulty keeping up with watering, unless you're very diligent.

Why not ask these questions on the ongoing thread you'll find a link to below? ;o) I'll be sure to see them & reply.

Al

Here is a link that might be useful: The thread