Nutes question ... close to harvest

Im using the 3 main foxfarm nutes plus ChaChing and im wondering how much of what do i use when im 2 - 3 weeks away from harvest.... Ive been putting everything in there but im so close im ready to harvest it asap... i heard to absolutely use chaching and on the can it says i can use just chaching but i want your advise.

Just give it water until ya harvest.

Yeah, you are definitely want to flush since those are not organic nutes (at least the Cha-ching). Just water or flush solution if you have it.

If it was me and in hydro, with three weeks left I would use chaching the next two weeks then water for the last week changing it out a couple times. Untill ppms of the res are like under 50 ppm.

With 3 weeks left i thought i was supposed to use nutes until a week b4 harvest.. like cruzer101 said... thats what i was thinking about doing... but im new here