Actually lowering Nitrogen in flowering is a myth
Weeds needs an ever increasing amount of all nutrients until the last 2 weeks of flowering.
All Nitrogen is to a Plant is Protein.
Human beings eat protein, and turn it into Nitrogen. Plants skip the eating process, and need to have the source already broken down to use it.
A plant puts on most of its Biomass in flowering.
Logically, does it make sense to limit Protein if you are say trying to be a successful Bodybuilder/Athlete? Does it make sense to limit Protein when you will be having the largest growth spurt of your life???
If you were an athlete, trying to maximize your genetic potential, would you Decrease Protein when you are training your hardest? No!!!
Athletes strive to maintain Positive Nitrogen Balance. This is also called being in an Anabolic State.
If one limits calories, or Macro Nutrients, the body will start using itself for energy, and is called Catabolic. Youre eating your self for energy/Survival. Same as when a plant goes Catabolic, the leaves start to Yellow, from the Bottom, UP. Its Cannibalizing itself. Which is BAD. Its in survival mode.
The main thing is to have proper NPK, Calcium// Minor Trace Elements and Micros.
Say one has an 8 weeks flowering strain.
From Seedling, until 2 weeks before harvest it will need ever increasing amounts of most nutrients.
Generally at 2.5 weeks flowering, through week 4 they will benefit from 0-52-34.. MonoPotassium Phosphate. Along with your Base Formula, which during this time, the Base formula will also slightly increase PPM each week.
Also this is if feeding Chemicals but one can also use Teas ect, and have an already fertile base soil.
In weeks 5-6 the plants will benefit from more Sulfur. I use Calcium Nitrate for my Nitrogen, and Calcium source, and Epsom salts for Magnesium, and Sulfur, soI dont use Cal-Mag s I get my Cal-Sulfur -Nitrogen/Mag from different sources than many that use cal mag, and dont use Calcium Nitrate.
In weeks 7-8, feeding is reduced 40%-60% until harvest.
Flushing is also a MYTH.