Semi Hydroponic Roting/fungi

[roguekiller23231]

i just received a 'semi hydroponic' Dendrobium, it's pretty big and the roots look pretty extensive, but at the base of the plant there is a lot of rot, white fungi and black, all over the roots that are at the top are also covered in rot.

the pot is also pretty poor, it's like a plastic tub with 2 tiny holes in it for drainage an inch above the bottom, so there is little to no airflow.

i'm a little reluctant at this stage to take it out of the 'pot' and re pot it, because of the amount of roots and not having a spare pot to put it in.

so my Question is, what should i do about the rot? i've heard cinnamon powder on cut ends helps prevent infection, would putting some on the area's of rot work the same??