i too don't like perlite because it's dusty, but that's interesting to hear that microbes don't grow on it...
So to follow that thought, a mix with 30% perlite has 30% less microbial life. Right?
On a tangent, and in response to some other post: It is not directly about the microbial count (IMO) when it comes to our systems and products(full of inoculants). It is about the microbial diversity, combined with what is able to survive in your mix, through many wet/dry cycles. By microbial I mean all beneficial microflora: endo/ectofungi, bacteria both free living and symbiotic.
Dumping microbes on all the time alone is not enough (IMO). Say the media is straight coco/perlite. Okay, that is literally one mill of coco, and perlite ranging in size but really all about the same. And if perlite is dead zone for microbes, assuming you always have enough air in your mix otherwise, then the perlite doesn't add to the rhizosphere microclimates. smoke break...
I would type a little "cough", but I don't anymore.
alright. So that mix is not diverse structurally. As nature has shown, diversity in structure equals diversity of organisms. Boo for someone who nurtures as much as he can out of the soil-food web using expensive fermented plant extracts. Let the tools do the work has always been my saying. In this case the microbes are our tools to produce flowers that are very close to flowers grown in top soil at natural rates (sub-atomically and in color), but at ACCELERATED RATES & INDOORS!
So no perlite means 100% natural. For the haters: My "one day you will me mine" potting mix, ala wayne's world: local, sustainable, extremely diverse in structure, as pH balanced and fluffy as the bio terra plus, and HOME-MADE.
I also really enjoy the low charge the terra plus comes with. The bark is one microclimate, the multiple mills of peat are a few more, the coco, then the gold peat is something else altogether, and sticks
. I believe it has a little guano in it...which is great. I'm not opposed to a little animal based organics, especially early. The terra plus is just so nice, and since the laws here are about compensation for expenses...