Roots turning brown

[ksriramkumar]

Hi andrew, how does it feel to touch the roots?. the roots inside the container look ok to me.

[bayswaterorchid]

Hi Ksriramkumar, the roots are generally firm but I did chop a few roots on the surface that became mushy.

A pic below shows aerial roots this phal had when it first came to me in December. These roots are now gone. What I find interesting is that those aerial roots have first turned grey and later became soft whereas the roots exposed on top of the pot have become brown. I noticed a few of them exposed in the air have gone mushy and brown so I chopped them off. The ones remaining on the surface are still firm and the roots sitting inside the pot looked pretty healthy as they look green. So I am wondering what's actually causing the top roots going brown?