What S/H media are you using? I use Hydroton in aircone pots watered every 3 days and have been getting phenominal root growth. I've ranted a few times already about my hatred of bark, so I won't rant again.
Basically you must find the "sweet spot" for moisture content. You want open media that stays damp or humid, not wet or soggy. It is hard to describe. It's like describing the ideal growing atmosphere to someone who has never been in an orchid greenhouse before.
Basically:
It's light, as in doesn't compress against the roots like dirt would and has as many air pockets as it does pieces of media.
Imagine soaking a paper towel with water and squeezing out every last drop of water you could. Unwrap it, and feel it. It's not wet, but not dry either. Damp even seems like too strong of a word, it's "humid". That is what the ideal root conditions for most Paphs is. It is hard to maintain with bark and other organic medias because the top will be dry, the middle will be soaked and the bottom will be damp. When you let the pot dry out, the top is drier longer so the surface roots are stressed and often the middle is just at the ideal dampness when you have to water again to keep the surface roots from dessicating. I always ended up dessicating the surface roots and rotting the middle ones, leaving a very unhappy plant.
This is why I love the expanded clay granules like hydroton or prime agra. You could water it 5 times a day, and it will only hold so much water preventing soggy conditions due to it's porostity and it dries evenly. Using it on a window sill, you may have to water daily since you likely don't have super high humidity making it dry out faster. I don't trust S/H personally, just because I don't like the idea of making paphs produce "water roots" in the bottom...just seems unnatural and bacteria ridden to me
For sphag and bag, you take a handfull of long fiber sphag and soak it with water. Then sqeeze out as much water as you can, then squeeze out some more(paper towel example above). You then fluff it up and place it in a ziploc bag and place the plant on top of it and seal the bag. Place it in lower light than you would normally for growing, but not much darker. In a couple months, you will have new roots growing if the base of the plant doesn't rot and kill it. Unfortunately, when you repot the plant, the roots are accustomed to the "ideal moisture/aeration" of the squeezed out sphag, and quickly languish in your regular potting mix from transplant shock and for the same reasons they did before you sphag and bagged them.
If there is more info you need, post it. I've done my share of experiments with this and "cuttings" and have photos of all of it somewhere. I currently have a couple small plants that started out as new growths that broke off the mother plant during repotting without any roots. They went into a sealed jar of barely damp sphag and have been in it for over a year. I've just been letting them go to see what they do, and so far so good.
Jon
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Gl1000