Leafs Are Curling Under On 1 Plant Only!!

titles pretty much sums it up. i have one plant that has the leafs on it have a under curl on all the leafs, and after 3 days (i was going to post when i 1st saw it, but didn't) the leafs seem to be getting a little frail, dry. i can only guess under watering over humidity...am i right? please help.

Plant Moisture Stress,Over-fertilizing,High Light ,Underwatering ,calcium deficiency.One of those more then likely.

You got it! Under watering and too much humidity...
Let her dry out only till she droops slightly then give her a good watering with 1/4 tsp H202 per gal
this will add oxygen to your soil and hopefully jump start her recovery
whats your average humidity?

average humidity is between 47-55. sometimes it creeps higher. thing is its the 1 and only plant out of 10 that is acting like this.

it really can only be the high light or the under watering. i could raise the plant up on a crate or brick.