Read the first two.
This has to do with build up in the roots. Nothing to do with getting nutes out of the plant.
In fact if flushing is real then having salt build up would help you flush the plant right?
The term "Flushing" is being thrown around and all the new guys are frantically trying to learn. The problem is, you probably watched a noob on video, wrongfully trying to teach that flushing is a tool used to get a chemical-free tasting bud with smooth smoke. Here's the real deal, and it's funny because I literally just when over this in another thread ...
"Flushing" or "to Flush", as defined by google is:
cleanse by causing large quantities of water to pass through it. "to flush the toilet"
It's the cleansing of "soil" because of salt buildup or ridding of nutrients within, by passing clean water threw it.
Flushing can infact be a very helpful tool if you use the term and definition properly.
Let start by saying that DWC can NOT be flushed, as you just dump the water and re-fill. You're literally just doing a water change. When the term is used in growing Cannabis, it's for cleansing Soil, and in some cases, media, and that's all.
Noobies are constantly confused as to "Flush" by cleansing soil, and to "withhold nutrients" at the end of Flower, to break the Chlorophyll's cycle, and speed up curing.
But let's back up a bit...
Chlorophyll is, in fact, the number one reason of harsh smoke or chemical taste. If it hurts to smoke it, it's probably not dried or cured wrong.
**Chlorophyll naturally breaks down without you doing anything to it***, as the nutrient uptake slows (also naturally), after it's lifecycle comes to a complete end. This is witnessed in nature all the time on all manner of flowers and trees turning colours. (note that chlorophyll looks green)
Now, the act of Flushing, for better tasting bud, is a complete waste of time, and aforementioned above, is infact, the misuse of the term; but let me explain...
Simply put, N,P,K,Ca,Mg,S,B,Mn,Zn,Mb,Fe,Cl, and Cu, have absolutely nothing to do with smoke quality, and in the plant at all times. Hell, they're in your mouth right now, as you read. Do you taste them? These elements build the plant as they're on the Periodic Table. What you taste is the compounds that they make, specifically Chlorophyll.
The best explanation of why some people forcefully withhold nutrients is to break the internal chemical chain of events within the chloroplasts, hence slowing or stopping the chlorophyll from being produced. Yes, this does happen, and Yes, your smoke may be smoother. But know this.... its not because youre starving your plants.
Again, Chlorophyll breaks down naturally. So why do people still withhold nutrients and starving their plants, you ask; Speed, and that's all. Starving the plant speeds up the process that breaks the chain in the chloroplasts, and effectively starts curing the buds faster. **But, theres downsides. Withholding nutrients the last week's before harvest, you're likely going to limit the full potential growth of your plant.
...Just one more time...Withholding nutrients is not the reason for better tastin and smoother smoke, the broken down chlorophyll, or lack there of, is. 'AND' Chlorophyll breaks down naturally anyways with proper drying and curing. If you'd like more info on this, please refer to wiki on why tobacco farmers cure their plants, here:
https://en.m.wikipedia.org/wiki/Curing_of_tobacco
Why anyone would want to hinder growth and yield for a week or two of time curing is beyond me. Why not just cut early, right? Why not quick dry, right? Heres an idea, if youre gonna spend all that time and money to grow, why not do it right, grow it right, feed it right, dry it right, cure it right, and not take shortcuts. Again, just an idea.
PS, anyone with a curious mind interested in learning more about the chloroplast within cannabis, here's a short clip on it. Expand your mind...., cheers.