dying leaf tip

[philoserenus]

oh my poor phal mannii, it have a couple of leafs.

the tip of the leaf is preceeded by a yellowing and dryness, and then followed up turning black little by little everyday. today is the 2nd day i've noticed it.

at first i thought it could be an humidity/heat issue but none of the other orchids i have in the growing area exhibit such characteristic symptoms. but could it still be this? i have a few small seedlings and even they seem to be fine...

itz not the oldest leaf either, itz the second newest.

im thinking could it be fertilizer burn, but again, only one leaf exhibits this... i dunno who took the camera but i will post a pic asap.

the leafs aint that big so it would take that long to have the whole leaf die off this way

please let me know if u have any clues