I have a thread on this somewhere. Flushing is a corrective action, not a necessity. For one, why would you want to strip your medium of vital nutrients during the most critical stage of the process?. You wouldn't, unless your medium was screwed up to begin with. If you use straight MG soil, you have to flush or your final product will have a distinctive soil flavor. Your grows are hydro, something I know zero about other than the fact plants uptake nutrients differently. In fact, I have read that molasses cannot even be used for hydroponics b/c the plant cannot absorb it?.