Your correct the coir contains smalla mounts of nutrients.  Not as rich as manure indeed.  In The Mushroom Cultivator coir is reffered to as a non-nutritional substrate, just because it contains significantly less nutrients than the nutritional ones.  It really is a matter of perspective.  A twinkie contains nutrients but i wouldnt call it nutritional.

  About perlite, i didnt mean to come off as making absolute statements. my bad, but i stand by the message, maybe not the wording.  A simple goolge search or small amount of research will tell you how well perlite works out for people.  Im not making it up it is factual information perlite is not "good" anywhere in a mushroom grow.  Can it be used? clearly it can the results are just not optimal, and often it will actually halt your grow altogether.  WHat i said was true IMO it almost never makes a good additive.  Not trying to make "absolute statements"  I think an absolute statement would be if i said, "coir cannont be used to grow mushrooms period! it cannont be done!"  i did say it almost never makes a GOOD additive, but heck i feel like that is true! at least going by my definition of the word "good" :lol:

Your picture proves it is possible to use perlite, it also proves the results are not optimal. and i mean no offense, that is a decent yield i suppose but could have been 10 times as good. I know its not a contest.