Twinkle Pink Profusion advice…

[lambo1972]

Would it also help to put a topping of sphagnum moss on top of the bark mix to retain moisture and/or some humidity? Would this help all my oncidiums? Thank you!

[estación seca]

A sphagnum moss topping might help, yes. You need to make sure it doesn't build up mineral deposits over time from evaporating wster. Be sure when repotting to set the plants at the proper level in the medium, with all the roots in the medium.