Do i need additives?

A question from a fellow grower:

The main question I have for now is whether or not I need to get additives/fertilizer for my plants. They are entering the vegetative stage and are growing in soil. I live in Los Angeles (warm and sunny all year long). I started using miracle-gro soil but found that might not be good for the plant in later stages. Let me know what you think, any advice is much appreciated.

Also, when do you suggest moving the seedling to a bigger pot, and what size pot do you think is best?

Answer these simple questions the best you can.
If you do not know, or do not use something; Just say so = NA

Strain; Type, Bag seed, or NA

Soil in pots, Hydroponic, or Coco?

System type?

PH of runoff or solution in reservoir?

What is strength of nutrient mix? EC, or TDS

Indoor or Outdoor

Light system, size?

Temps; Day, Night

Humidity; Day, Night

Ventilation system; Yes, No, Size

AC, Humidifier, De-humidifier,

Co2; Yes, No

Add anything else you feel would help us give you a most informed answer. Feel free to elaborate, but short, to the point questions and facts will help us help you smile