prag penn's creek - leaves turning brown and leathery

[klkelly]

My mom's orchid needs help. We bought it at an orchid society sale and we really want to save it.
It says "prag penn's creek grande 4N4 wallisii"

We have been following the instructions and its done great. My mom went away for a month and I brought it to my house. It did very well the last time I had it also. This time it started to get a black tip on one of the leaves.

My mom got it back last week and since then its going downhill. She described it to me clearly: it gets brown tips, then the edges go brown and then it goes all leathery.

Can you guys help. I can't find this out with any certainty using google. My mom said she used new scizzors to cut off the leaves.

I kept it with my other two orchids but it was with them before. I have three NoIDs from the grocery store of course but keep these separate from the orchid society orchids (I have two different types not the same as my moms).

Thank you for any advice.