Blue crayfish molted again!

[ShawnKC]

My P. alleni molted on Halloween and then again last night. he seems to get a deeper blue with each molt. I removed the first shell mistakenly thinking it was the dead crayfish since I didn't see the molted cray at the time.
I have read that they will eat their shells after a molt to ingest the needed calcium from the shell. I was wondering if the shell will eventually start to foul the water if I leave it in. Since I only see him peek out of his den occasionally during the day and he is only active at night, how long do you think I should leave the shell in the tank?

 

[sansouci01]

When my cray molts I leave his old shell in for a couple of days. Any longer and I'm sure it would not be good for the water quality..

 

[Tetra1990]

Yes, just like leopard geckos, leave the shell in for a day, it will eat what it wants. Any longer and it will funk up the water. Beautiful crawdad btw.