yeh many of the main companies that make hydro food have these additives in their range of products (nitrogen fixing bacteria)
this shit is expensive
here is one example
VitaLink BioPac .. company sales pitch below
Adding VitaLink BioPac to your nutrient solution will establish a population of beneficial fungi and bacteria within the growing media. The fungi and bacteria dissolve nutrients so that your plant can absorb them easily and quickly. In particular, they dissolve Phosphorus and fix Nitrogen, two of the major nutrients your plants require. The fungi and bacteria also improve the processes that encourage optimum uptake. Nutrient uptake and transportation of nutrients are further improved by the Humic and Fulvic acids VitaLink BioPac contains.
Overall, this leads to enhanced yields and crop quality.
With 37 beneficial microbes, VitaLink BioPac contains double the amount of microbes you will find in a similar product.
Just some of the microbes include: Trichoderma, Bacillus bacteria, Mychorrizal fungi and enzymes. This high microbe content ensures full bacterial and fungal colonisation of the roots occurs quickly and efficiently, inevitably speeding up root growth. In turn, this aids propagation, vegetative growth and flowering.
Many of the beneficial bacteria and fungi within the BioPac help to prevent fungal infections on leaves, stems, fruits and flowers, such as Leaf Spot, Powdery Mildew, Downy Mildew and Botrytis. BioPac also has some activity against leaf dwelling insects and will assist in the prevention of Spider Mite, Mealy Bug and White Fly attacks. For pest and disease control, use as a foliar spray
For the best results from your plants, use right from propagation