Root rot after SH to SH repot (phal)

[sunfire]

Hello all!

I recently repotted a phalaenopsis who had been fully adapted, grown well and bloomed in S/H back into the same S/H container. I thought the repotting went well and was very pleased with everything at the time. I originally transitioned this plant from moss to semi Hydro with no problems.

The pot got knocked over a week later and when I went to put it back together I was really shocked to see a lot of newly rotten and smelly roots that were not rotten beforehand. The root system previously was very robust and now is minimal which has me sad and a little concerned. The plant is otherwise large and healthy. One of the leaves is senescing as is the flower stalk but everything otherwise still looks good.

Is this normal to see with a semi Hydro repot? New roots were actively growing at the time and they still seem ok although the fleshy part of the root tips seem to have dried.

A separate question - as the roots grow into the semi Hydro medium the pot becomes more and more compact. How often would you repot a orchid in semi Hydro in this situation? It seems to me that with less space available for air (with the former spaces having been taken up by the roots) in this always wet environment not good things might happen....?

Thank you.