Mesh independent solution

CFX Begineer

I have been reading several old forums about the mesh independent solution. However, when I try to refine the mesh by reducing the mesh edge length in CFX build, there's always a message telling me the min value I can set for this length.

Why there's a limit for this length?

I set the same value for min & max edge length to get a more uniform mesh in my model. What do you think about this?

Will the solution always be mesh independent at this value? If my solution is still changing when I reach this min value, what else could I do?

I haven't done any mesh independent solution before. Thus, any criticism or comments are absolutely welcomed. Please share your experience.