That depends. You only use TEA when you are growing in organic setup. The TEA can be one of 2 types. Either it is a microbe tea that is specifically for adding new microbes to your organic medium, or it is a nutrient tea that is either raw materials dissolved into water or partially/completely chelated raw materials made into a feeding solution. You can do this in DIY or from commercial organic tea.
The commercial organic tea will either be in "grow" or "bloom" formulas. If you are using this in your organic medium, it should supply most if not all of the nutes needed for that stage of growth.