Grojak, you missed the subject the OP and I were discussing. He was asking about pre-harvest flushing and you are arguing about routine maintenance salt build up flushing which is something completely different.The "mother nature does not flush" argument is getting old…. you're not following mother natures plan unless you're growing 100% natural organic in the ground (bat shit, worm castings ect..)
Mother nature does not use man mad (synthetic or organic) nutes so this argument is bunk. The nutes that 95% of growers use cause salt buildup and nutes remain in the medium and ppm on run off can get crazy, do non flushers ever check their run off? If you're 3 weeks from finish and your run off is 2k ppm and up not flushing ain't going to help anything you need to get that down low I water just ph'd water every other watering (though I've found a couple strains that don't dig that method, fixing that next time i run them) doing so keeps my run off ppm low and I just water with ph'd water for the last 2 weeks, no flush just normal watering. If you're watering every time with fert (and don't have a way to check your PPM) I would at least water with ph'd water the last week or 2 and if your ppm is way up there like I mentioned before… I'd do a flush at 2 weeks (run multiple gallons, if you're in 5gal pots use 5gal water is a safe bet) than just water with ph'd water as needed.
hth,
Annie