Encyclia Cattleya hybrid leaves turning brown/black from top to base

[Shamu]

I’ve had this Cattleya peckhaviensis x Encyclia Paula Gross hybrid for about a year with no trouble. I saw new roots starting to emerge, so I repotted it in a mix with some sphagnum because it was drying out too quickly for me to keep up with the watering. Other than that nothing has changed in environment— it has a sunny south facing window with a humidity tray and watered with distilled water. However the leaves had been getting yellower, still green though, before repotting. Many of the roots were dry and brown (dead) when I repotted, so I cut them off with a sterile set of scissors (rubbing alcohol). I didn’t see any bugs and I still don’t see any.

Any ideas on what this might be? Should I be concerned?

[Nexogen]

The photo is not eloquent. When the plant has no roots, it is normal to consume energy from leaves and pseudo bulbs, probably there is nothing wrong, just the shock of moving into another pot. Be careful not to bury pseudo-bulbs too deep, keep the plant in the shade and wait.

[dounoharm]

I think a smaller bark mix would be better for that plant....while you want roots to develop, keep it more shaded also....good luck!

[estación seca]

I wonder whether you have spider mites. The leaves look that way. Take a tissue and rub leaf undersurfaces from the pseudobulb to the tip. If you see brown or reddish streaking you have spider mites.