made this a couple of months ago...saved it as .exr but had no time for postwork...well...then i forgot it ;D
the image developed out of a voronoi test...first i had some nice ice floes which were rather boring ;) ...so i changed it to a night scene...but the ice didn't look that good in the distance...that's why i put up the icewall...
I would turn some of the ice a light blue.purple. Like light which has been filtered through ice. It does not want to be too dense, but just enough in the right places to give the ice some translucency.