3 things come to mind

1) was it in medium bark to begin with? Usually, the rule of thumb is to use
bark in the same size as the size of the roots (fine roots = small bark) The
medium bark might be too large for it and its drying out prematurely.

2) did you premoisten the bark prior to using it? Lots of times the bark has
a bunch of dust and dirt in it too and this adds salts to the potting
mixture, which the roots pick up and causes leaf tip die back. Pre rinsing,
pre moistening cleans the bark.

3) I forgot what the 3rd thing was.... It'll come to me and I'll repost
unless someone else comes up with it 1st. *G*

Anyway, you could try covering the medium bark with sphagnum moss in an
atempt to hold more moisture at the roots if repotting it in finer medium is
too much trouble.

K Barrett
"Paulo" wrotein message
.. .
Hi everyone, some time ago I was commenting about my OF it started to grow
for the 2 oldest pseudobulbs....Well now this new little leaves are
turning
brown. I have repotted recenlty in a mix of medium size bark....I dont
know
if need more water or less...right now i am watering twice a week, when i
notice the bark is dry.....Any suggestion?

--
Paulo