Leaves Change color/Drying out/Curling up and dieing.. WITH PICS! plz help..

Hi everyone..
so im not to sure whats happening to my plant, it seems to be slowly dieing..
The leaves are drying out and changing color and Dieing =(.. I dunno whats happening..
It gets the same Water and feeding schedule as my other plants and there doing fine!?.
Heres some pics..

..
Anyone?

lol idk if it was u or not, but ill say this again, you have either a magnesium deficancy or a calcium deficancy. see the edges of the leaves? see how it just starts at the edges and works it way to the middle? check it out man.