Need help with Brassavola nodosa rot

[Conjuration]

Thank you for your reply! I'll remove the topmost layer of pumice (should do the same job as lifting the plant out a bit).

Originally Posted by Ray

That's why the best time to repot is right when new roots are emerging from the base of the plant; they will take over the support of the plant while the old ones die.

I did repot while new roots were emerging (she was blooming and growing a new leaf at the same time). It's just... the new tips all died.

Originally Posted by Ray

including prying bits of bark off of them (which was not totally necessary)

Oh, I actually thought organic medium inside a semihydro setup would rapidly degrade and rot the surrounding roots and was quite meticulous about removing the organic matter...

Originally Posted by Ray

At this point, you're in recovery mode, so in addition to elevating the plant a bit in the medium so that the root/leaf junctions is at-, or above the medium surface, you're going to want to keep the plant very warm to induce root growth (seedling heat mats are good for warming the container of medium, which favors that).

I can add heating to the bottom of the pot. Should I also place a fan somewhere in the vicinity? It would increase airflow, but also cool down the plant (probably too much with the dropping winter temperature). Airflow or warmth, which one should I aim for?

Originally Posted by Ray

Application of a root growth stimulant would also be good, but I don't know what's available to you.

Rooting hormones (NAA, more specifically) are popular and cheap here. But I can definitely find seaweed extract too.

What about the rotting new leaf? I believe I ought to cut it off (at the base I think). Should I do anything about the rhizome? I don't know how the rot spread from the sick old leaf to the new leaf (they weren't even touching) or if indeed the two leaves contracted the same disease.