Orchids potted in sponges - what to do

[Roberta]

When removing the old medium, you don't have to get it all. Just remove what you can get off easily, where it is stuck to roots, leave those bits, The roots will adapt to the new medium, eventually that stuff will fall off. But as long as there is not a lot of it, won't really affect the watering regimen much. Same applies to plants in sphagnum. You don't have to get them completely clean to gain the benefits of the new medium.