I have five phals in full bloom. Most are also growing new leaves and
most have roots growing on top of soil.

I understand the potting mixture tends to break down and should be
replaced regularly. How often? How often do I need to increase the
size of the pot. Sounds silly, but I'm running out of space and if I
have to get bigger pots for all five plants I'll have to get rid of
one, which I really don't want to do.

Another question: I tend to water my phals every 10 days or so but I
notice that the top of the soil get very dry. I've been misting the
top every few days. They seem to like it, but is that a good idea?

Finally: I have an oncidium that hasn't been in bloom for about 10
months. It's growing leaves like crazy and is also growing very fine
white roots. I have it in the same place with the phals. It gets
strong, filtered sun for about 5 hours in the morning. If that's not
enough light then I will have to let someone else adopt it. Should I
give it away or wait a little longer?

thanks!