How long time is it left to the drying process

From just the one pic you uploaded I would say not to long. prob close to 2 weeks give or take. You want to judge the readiness by a few factors. Is the plant slowing down on its growth?, Is the plant starting to drink less?, Is the plants pistils mainly dried back about 80% of them?, are the plants trichomes mostly milky? if yes to all of them or most of them its likely time for a chop. You can stop feeding them extra stuff about 1-2 weeks from cut. when doing this, don't flush them, just give them PH'd water and don't get any runoff like your normally would. let it use up any and all of the nutrients in the medium, as your not adding any new ones in, no point is getting extra out. Same with dry amendments. just water no flushing. Fluching is a bro myth same with any length of darkness before harvest.