Marijuana is a cal mag monster.Always add it to everything.The theory dont give it to it if it dont need it..well..it needs it..and it needs it bad and yes it is part of getting your grow dialed down and maintaining the best health for your plant.
Another thing that will keep your plants in tip top perfect shape is azomite .It is a mined mineral with every known micro nute your plant could ever want.You will never had a deff of any kind using it.
Silica.This makes your plants stems strong able to hold more weight,also makes your plants more drought resistant. also keeps plant resistant to PM.
Humic and Fulvic Acids.These makes your roots soft and melts the nutes so the plant uptake of the nutes better.
One or Two drops a gallon of super thrive(Vit B) This if you want to think of it as a energy drink for your plant.
Carbs,Molasses ,ext.Made by about everyone take your pick.
Adds starch and carbs .Same as body builders increase carb intake to get BIGGER.
All this being explained, do you have to use all of this to get a nice plant? NO.
It is a good idea to use it if you want to keep your plant in max health to produce to the best of its potential.
I didnt even mention feeding.Almost all of these items are just considered more for the health of the plant and have what is needed to assist the nutes in bud production.
You ever have PM? Whats it worth to keep it from ever happening?
You ever miss a watering or have a pump failure? whats it worth to come back and have your plants still alive?
Whats it worth to NEVER have a micro problem again?
Whats it worth to increase your size quality and potency of your bud?
You know how many times i hear someone on here say..oh man.i had to leave town for whatever reason and come back and stupid brother in law didnt water the plants and they were all dead..or someone who had a pump failure comes back in the next morning all all of his shit was dead.
How about the ten million questions from people on here..whats this ..whats that deff..all of that shit can be solved with some micros or azomite.Azomite cost like 40 bucks for a 40 lb bag and it will last like 200 years.
Walking on on your plants them 6 weeks into flower and every thing dead.WOW..you just wasted at least 2.5 to 3.5 months and the money you invested.You talk about heart breaking.Almost as bad as a male plant popping nut all over your bitch's when you aint looking.
Or spider mites.WOW..i really hate those cock suckers.
If your shit is good and healthy..when a problem happens..and it will. you will see it faster and be able to correct it faster when you know ALL other variables are covered.
I hope this opinion helps.