Adding to much/alot of charcoal to medium is it good or bad?

You can grow them in straight charcoal if you want, I have. Charcoal doesn't retain much water, and doesn't break down, so can help keep a medium from getting soggy. Supposedly it's porosity helps with ion exchange and absorbing organics, etc. I don't know how much that matters overall.

In my opinion, much mixology is of the notion that "This is what everyone says it will do, so it does" but with not too much documentation to back things up.'* Ray may actually have some science for this, however.

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* Basically, Senior Lifemate Stories

 

If you have hard water it could be an issue.

 

Like Carl, I have grown in 100% charcoal, but despite its seeming lack of decomposing, it is really a relatively short-lived medium.

I imagine that the degree of "activation" in horticultural charcoal is small, but it is still very porous, and it grabs and holds stuff really well, meaning that minerals and plants wastes can accumulate in it fairly quickly (I suspect that was the issue with the hard water, mentioned above), making it toxic to roots.

 

You'll go broke using it on orchids.

Also, it's utility depends on the particle size.

 

In addition to Carl's astute observations, it's actually worse, as the activated charcoal will hold onto things even more, accumulating them faster.

 

I have used tree fern fiber and perlite to keep moss airy with good results.

 

Charcoal wont have a detrimental effect if you don't use too much. The charcoal and especially the coconut husk will hold salts from any fertilizing. The way to avoid salt build up is to flush with good clean water ( rain or RO water ) after every feeding. Everything else you mention is fine to use but bark plus perlite is sufficient for nearly all orchids.