The4ekdon: Here's what we've been getting from school. They recommend flushing between each change in the type of nutrient solution to wash out the accumulated salts. In other words, from the veg stage to the flowering stage they recommend a flush with pH balanced water for three days to a week before actually changing to the new nutes.
I've never have done it that way. The only flush I've done was at the end of the flowering stage just before harvest but the instructor who's advising it is making me wonder if I'm missing something. I even stretch my flushing. I use Technaflora's, "Recipe for Success," and it recommends a pre-harvest formula that's supposed to be used up to three days in the last week before harvest then a pH balanced water flush.
I leave the pre-harvest flush in for a whole week and then I drain it and give them a final flush with pH balanced water for another week before I pull them. I can tell you one thing though, mine tastes better than my friend's who only does the final flush without the pre-harvest flush. I haven't found too much on this in the past and I fear I may be doing it wrong but it works. Now I may be starting a pissing contest. HSA