I will throw my 2c in, just so that you have heard it once. I come from a new school of thought; that is derived of old school methods and new school research and testing.
I used to also believe in giving only water, or of course water with molasses, at the end. I did it many many times and had great success in those grows and truly believed that this was the way to do things. I however did not call this starvation diet at the end, a flush. A flush to us old school folks means moving 3x the container size of water through the soil, so as to cleanse the soil of any old nutes, debris from broken down organics, and salt from the breakdown of synthetic nutes. In the old days we clearly recognized two processes that were separate and distinct from each other... the flush cleansed the soil and the starvation diet at the end cleansed the plants.
Now thanks to modern science, you know, that pesky thing that has allows us today to grow much stronger pot than ever before, has done testing on our buds after harvest. It has been determined that this starvation diet does nothing to change the taste of our final buds after curing. It is a waste of time and an error in thought to believe that we can or should cleanse the plant at the end.
There is however, a proper time to do a proper flush. Any time during the grow when you see water use stagnate when using synthetic nutes, it is very possibly that the salts have built up to the point that it restricts water uptake into the roots. A quick 3x flush on your water only day clears the soil and gets things going full speed again.
One of the most important times to do a flush is in the last 2 weeks of the grow, when the buds have entered into the final stretch, where they can double in size and weight. Full uptake and full nutes can be used to great effect during this time, and I now know that much more massive and flavorful yields can be achieved by feeding right up to the end. Giving a proper flush right before the final push toward completion can supercharge this process.
People who do not want to go to this effort will say that they don't flush at the end and did just fine, or that they give only water for the last week or even two, and got a great yield. Just imagine what could have happened if you used the finishing nutes to supercharge this ending after a properly timed proper flush, giving the plant everything it could use to finish, along with massive amounts of water! Those who are skeptical should try a side by side test of these new methods... you will see. Ask any organic soil grower... they already know what plants look and taste like that are fed right up to the end.
Thanks for the input and the reminder that a lot of the benefit from molasses comes from the trace elements that it both has and that the plants need for full bud development! I am of the firm belief that we still don't know what we don't know about the actual needs of a weed in full bloom, and that certain trace elements available in volcanic soils and indeed brought in with inputs as complex as molasses or dandelion extract, (remember the SuperThrive product too) are key to achieving a full expression of this plant's abilities.
