Beneficial's are Bacteria and fungi that aid plant growth. They come in powder or liquid form. Its apart of the make up you may find in the micro ecosystem in organic soil. You can cultivate your own in liquid form in what we call a tea mixture. Hydroponic shops sell them ready for use like the liquid aqua shield which is derived from liquid compost or things like ocean forest or great white and so on and so forth.This is a question from ignorance... What are beneficials?