questions about moving phrag to s/h
 

I just have a few concerns about moving a recently acquired phrag to s/h. It is starting several new growths, so I'm not too worried about the roots. Mainly, I'm wondering 1) whether the top layer might get too dry, 2) whether the evaporation can chill the roots, and 3) whether s/h can amplify issues with high-ppm tap water.

1 is not likely a problem. Roots will extend well into the pot now. Frequent watering will keep new roots healthy as they grow down into the more moist layers.
2 yes, the evaporative cooling happens. Phrag. schlimmii is a cool to intermediate grower. This won't likely hurt in winter and will probably help in summer.
3 if you water frequently this is less of an issue. Don't water so seldom salts build up on the top layer. Periodically flush and soak with rain, RO or distilled water. Put it outside in summer rain. Don't forget to bring it back in before the sun comes out.

I put the Phrag QF Maria I just received from Ecuagenera into S/H right away, without worrying.