First Grow

HI there, this is my first post and pictures form my first grow. 

I used Rye Cakes with Calcium Carbonate.

Im afraid that me putting tin foil in the terrarium messed the mushrooms up, the first two cakes i used the lids from the jars to set them on but as you can see I used tin foil on the latter cakes and after a while the bottom of the tin foil that was touching the Pebbles turned a dark silver. Some of the mushrooms would pin and grow to about 1in and then stop growing... Any Ideas? Thanks.

 (I'm probably going to post this problem on another thread too.)