what to do with sick phal.

[playtime8978]

I posted some time ago that I managed to give one of my first Phals. root rot and it was rather poorly all the leaves are floppy and there was only one really viable root left and two aerial roots which is tucked into the new bark. My question is what should I do with it, a month on it has done nothing, it has not died it is still holding on to its floppy leaves but neither is it showing any signs of new roots its in low light and watered infrequently. I was thinking of semi - hydro but have read that that might not be the best plan for a sick plant, sooo I am open to suggestions this guy obviously wants to survive as it is not dead yet so there must be something I can do to give him a fighting chance. Thank you in advance for your help.