@Jimdamick
I do know what I'm adding. I am adding microbes and life to my soil. My soil mix itself is based on Clackamas Coot's recipe soil my soil has all the nutrient the plant needs. When adding earth worm castings and kelp meal add microbes and food for the microbes. It's the microbes in the soil that break down nutrients to feed my plant. The plants roots put out exudates which feed/tell the right microbes to bring in the nutrients the plant needs at the proper time. Nature has been doing it that way since the beginning. And the microbes will bloom and die off as they are needed naturally. All I need to do now is top dress with a wide variety of food for my microbes and the plant and microbes do the rest. The only time you might have deficiencies or excess amounts of anything is in the beginning as the soil is balancing itself out.
You have only 90 days to establish a viable root system in an indoor grow.
Your talking like creating a healthy soil indoors takes weeks, it doesn't, it takes months for the microbes to develop into a healthy system, and by that time your plant is finished.
So, my point is this.
In an indoor grow, in soil pots which usually are around 3 gallons, or even 5 gallons, the activity of microbes needed to breakdown nutes in the span of 8 weeks ain't gonna happen, it's fucking impossible, and expecting to develop a healthy, living soil is a pipe dream.
Soil does become contaminated, and reusing it time and time again is counterproductive to the simple fact that I needed to grow the best plant possible in the shortest time available, so I used to use fresh soil every grow until I went pure hydro.
Soil is a wonderful thing in a perfect world, but indoors, without natural rainfall to cleanse it, or worms to break down dead organic matter and other microbes to de-toxify it, it sucks.
That's why I have been growing hydro for the last 20 years, because soil actually sucks for indoor grows.