Its pretty amazing, this thread most say no flush, yet a thread days before this one
https://www.rollitup.org/t/flush-vs-dont-flush-argument.1030461/ most say you have to flush.
So have fun with that. Personally I do both every grow, because I have 2-4 week harvest. I can't really tell a difference in taste, smell, ash, due to flushing. Other factors seem to be far more important on taste, smell, and ash, such consistency and timing of humidty/temp of grow and dry. ie vpd. Harvesting the same plant over 30 days, also changes those attributes, for me it seems the optimal window of harvest is somewhat narrow, like maybe 1ish week. Before or after the optimal window I experience different/better/worst taste smell,taste and ash...
The agreement that flushing pulls out 'nutrients' and 'salts' I've yet to see any evidence of. I think people are combining to many commonly known facts, such as how ions cross, some, cell walls due to differences in ion contractions across the membrane. And trying to apply that to flushing. But it does feel like there maybe something applicable to 'flushing'. I guess thats why this discussion will NEVER die.
Usually I lean towards flushing, because there are indisputable advantages such as lower cost...
Until there is actually peer reviewed funded studies taking place, all of this is pseudoscience, and I've found due to other factors it may seem that a flush works on 1 grow but no difference on another. Basically blaiming a flush or lack of as the only factor to influence these important attributes.
I did watch the nutrient company RX youtube and read there supplied materials, that still isn't adquate to prove anything. As for that, don't believe everything you see on tv, or youtube, or internet forums. There is no rule, law or otherwise stopping them from falsifying everything they say. Also watch some more MIGRO videos and credibility drops FAST.