What to do if roots are rotten?

[Lef1223]

Hi my name is Linda and I am very new to the orchid world but recently became interested in them, so today I joined this forum, as I seem to be struggling!
I had an orchid in lava rock to try and prevent the roots from having problems because it had actually gotten snow mold while potted in a previous medium. So I switched it to lava rock per someone's suggestion. But now I am realizing the roots are rotting so I am going to try and eventually convert it to the water method! Right now I have it bagged with a small amount of water in the bottom of a glass vase with some rocks at the bottom for structural support. I don't have any sphag moss though. Do you think I will still be able to save it? Should I add anything else to the inside of the vase or the water? Should I keep the bag around it all the time or ever let it air out? I really appreciate any help or suggestions!!! I will try to attach a picture of it in its current situation too! Thanks so much!