I just received a shipment of 1 crypt willisi, and 2 crypt wendti from TFP.  
They looked pretty good out of the box, but as soon as I planted them in my 
tank, the leaves began dropping off.

My question is, is this natural for crypts to loose their leaves upon 
Also, will they grow back, eventhough they have no leaves left?

My tank is a 42 gallon hex with 2 angels, 4 corys, and on Otto.
Gh = 4 degrees
Kh = 2 degrees
Ph = 6.8
Lighting provided by a wonderlite (full spectrum)
Substrate is vermiculite mixed with sandy soil, and one inch of aquarium gravel 
on top of the verm/soil mix.
Fertilized by plant tabs in the root system, and tetra blackwater extract.

P.S. the Amazon swords and Vallisneria I received at the same time from TFP 
looked great and are doing great in the same setup.  Is it just a problem with 
the crypts?