vanda root question

[tokart]

I've had these two vandas for about 15 months now.
the one on the right has its first spike and bloom as you can see. Very excited.
My question is about the one on the left.
As you can see there was a good root system at the bottom but now this seems to be drying up. there is a healthy root growing about 5 inches up from the original ball and all the lower leaves have fallen off. My question is - should I trim off the bottom roots and let the new upper system grow or just keep spraying both.
These are my first Vandas and my first post.