In hydroponics, plants will grow just fine using only mineral salts. Plants will not grow at all on a diet of only PGRs. Therefore, the salts are a little more necessary than the PGRs. While plants manufacture their own PGRs internally, there are compounds that can stimulate or inhibit that ability on demand. The problem is that some of them were developed for the ornamental plant industry. They are used in such minute amounts that they would not have any negative effect on a drip system for sure but the health consequences are undetermined as of now. As far as carbs, they belong in the organic gardens where all those live things in the soil could use some extra food to multiply and thrive. Of what use could they possibly be to a hydroponic guy in sterile media like rockwool or even coco? There are at least two elements in a good hydro formula that are antagonistic to soil cultures. It just makes no sense if you understand that fact. And an interesting note about "organic"....the state of Washington has a classification of fertilizer called "synthetic organic". Organic fanatics know the definition of "organic" as something that is derived from a carbon based source like compost, blood meal, kelp, etc. Some bright person figured out how to take a base element like phosphorus and bond it to a carbon molecule giving it similar performance characteristics of a true organic source of phosphorus like bone meal. Hence, "synthetic organic".