I flush a good few times through a grow cycle,once at the end of week 3 after big buds been in the plants system for a week or 5 days.I don't go on a time with big bud just 2 ml per ltr along with canna a/b in a 20 ltr tank once they drunk that normaly in 4/5 days sometimes faster.then again just before pk 13/14 at end week 5.But these flushes are only for 24 hour.
Because i'm growing in hydropnics i don't feel ya need a longer flush in this method beacuse the roots up take the water faster than in soil,eg water direct to the roots,then they are taken up by the plant into the coco where the plant utilise's the water.
Then i flush for 12/14 days if the plants are at there best 5/6 ft trees,if i do the blues that stays smaller and 7 days flush is fine,i don't use anything like final phase,never have i know people who do who say it gives you better tasting bud,but i have tried it and i can honsetly say i can't tell the differance.
Ther nicest tasting bud i have ever smoked was most wanted from orange hill,near to where strain hunters was filmed and that tasted the bee knees but i think that had a lot to do with the water they use there,its a little salty,but dam fine bud,,
Also go to turkey every year i have a friend who runs a hotel there he grows some of the biggest trees i have ever seen emril triangle
style he had one a few summers ago 16 ft,i only seen it at week 7 and it looked mousive,but he only does the seeds i take him.
for some reason they really struggle there for seeds,
I took him some super silver haze seeds about 6 year ago and that is all he grows now he bungs me a ozie every time i go so i always have good holidays there smashed it hits ya more in the sun.
I made him a auto pot set up last time we was there took me about 1/2 day he is still useing the same system to this day,only problem we came across was i had to use adapt a toiliet ball cock to each big not tub but he loves it.
he only uses hessium sacks full of cow and farm yard shit put into the feeder tub,then just give the sack a shake very so often he knows on the coulour of the water when he needs new organic feed t for the plants they love the stuff,but farm yard shit is far better than just cow horse or any shit because it has urine in it the plants thrive on it.
Going there this year so i take a few shots,i don't like takeing photo's in turkey of plants though i have seen midnight exspress too many times lol,but im happy to sneak the odd few beans over.i will be takeing him some cheese and timewreck cross this time its time that people got the real cheese instead of the seed company versions because i can honestly say not one of them have the real cheese.Not even big buddah,the cheese them and greenhouse sell have the clone only traits some of them but its far from been the real deal.
I also know growers that feed with nutes then water then nutes then water and so on,they do ok that grower gets around 100 oz dry from 9 plants.But he only feeds like that through veg in flower he pretty does what i do the odd day flush 24 hour here and there
hope this helps any questions just pm me