Myco is what are generally referred to as beneficial bacteria/microherd. For organic growing they are essential to break down organic matter into a form that the plants can use, salts. Hydro nutes are the salts that plants eat so no microherd required as they are easily absorbed by the roots and immediately available to the plants. That's why dirt farmers mix up and wet the blends they use and allow them to "cook" to allow the microherd time to break down what's in the mix and turn it into plant food.
Many organic enthusiasts claim that chem ferts added to living soils will kill the microherd and in max doses might damage them but have no problem adding some epsom salts to boost Mg and it's the same thing as the salts in hydro nutes so adding lower levels of them can boost plant growth without hurting anything.
Adding carbs to your soil isn't for the plants so much except indirectly as it's food for the herd so they thrive and produce more food for the plants. Some of the sugars are absorbed directly by the roots but not much as the plants make their own sugars through photosynthesis using carbon dioxide from the air and circulate them around the plant much like our blood circulates around our bodies.
I have an old bag of ProMix BX that I keep around mainly for rooting cuttings destined for use in DWC as it doesn't have myco which I don't want in my tubs. Basically the same thing as the versions that do but could use more coarse perlite to aid porosity. The HP in ProMix HP stands for High Porosity and comes with more than enough perlite to use straight out of the bag like I have done. I'm mixing it now with the Veg and Heb mixes and their potting soil mix as it seems to grow very healthy plants that don't even need nutes until they get bigger.
Adding more perlite to your BX will probably cause you to have to water a bit more often but will help get air into the root zone more often too and that's a good thing. You can buy various myco additives to add to soil mixes to boost their populations if the soil is lacking but in a healthy living soil with compost and things like worm castings they'll breed as long as they have food like sugars to thrive. Un-sulfered blackstrap molasses is a popular additive to supply needed sugars for them and a hell of a lot cheaper than most manufactured ones.
bravo!
Don't need the myco in there for feeding hydro nutes anyway and if I want bennies in a soil grow I can just water once with my dugout water to supply those I bet. Lots of frogs and little fish living in my dugout so it must have a healthy dose of all sorts of bacteria and fungi.
