Originally Posted by Tikva
I should preface this with "I have never tried to grow a vanda inside my home", so this might not be the best solution.
First: I would not try to remove it from the basket. Usually we just sit the first basket inside another larger one and wire them together.
Second: What I would suggest for you is to take some spag and put it in the basket to help hold a bit more moisture to the roots. Don't pack it in, just some in the basket to hold moisture.
BTW, Does the plant show any signs of needing more water? If not, perhaps some of the root shrinkage you are asking about are just part of the cycle of life. The thicker roots are up higher on the plant and the thinner ones are down on the beginning of the plant and may not be being used as much anymore for actual support.
We grow our vandas in the GH in baskets and have had much success with lava rock and wood. The smaller ones get a bit of Spanish moss or spag to help hold moisture between waterings, and because the Spanish moss looks really cool hanging off of the baskets as it grows and blooms.
So to recap: do not remove from original basket & add a bit of spag to the basket to help hold a bit more moisture. JMHO