Sounds like a mixed bag of potential issues.

First the easy one: Dip a soft toothbrush in soapy water (on the lines of
Joy or Dawn), and gently scrub both sides of all of the leaves. it will
clean up the deposits and remove the scale insects.

A general stalling of growth could either be directly nutritional, so share
the fertilizer formula, strength applied and frequency so we can look at
that, or it may be that the medium is in such bad shape that it is stressing
the plant and possibly has damaged the root system such that they cannot
absorb water and nutrients well.

--

Ray Barkalow - First Rays Orchids - www.firstrays.com
Plants, Supplies, Artwork, Books and Lots of Free Info!


"Leon" wrote in message
oups.com...
My phalaenopsis have done all right in the past. But now they have
stopped developing new leaves for some six months and the existing ones
do not look well. While they are deep green, they have secreted
something that looks and feels like a water-clear, dry varnish that is
spread out very thinly and in patches, mostly on the top surface, but
also underneath. There are also a few brownish scales, some roundish.
Any idea on how I can bring the plants back to life? Should I wash the
leaves, and if so, with what? Is lemon juice a possibility? Should I
repot them? Thanks in advance for advice.