Lean and flush or straight flush?

You are way off for most of the plants ................3-4 weeks. Only one looks about 2 weeks away. Personally, I like to stop all nutrients and supplements about 10-14 days before estimated harvest day and just give plain water in normal amounts and at normal intervals during those last 10-14 days as a "flush". I generally dial back the (estimated) last feed before the "flush" period, otherwise feed as usual. For "flushing", there is no need to drown your plants with gallons of water in the hope that it will magically do something. As a rough guide, I stop feeding and start my "flush" when there are about 95% brown pistils/hairs and harvest 10-20 days later when there are 98-99% brown pistils hairs. This co-incides with the oft quoted "10-30% amber trichome" recommendation without having to be too anal about it.