First time in soil need advice with flushing

i am using sunshine mix #4 with general hydro flora series plants have been in flower for 3 and a half weeks today i would like to flush them and let them dry out to get oxygen to the plant therefore boosting metabolism but im not sure the way to do it im on 900ppm right now so doi flush with straight ph'd water and flora kleen or do i drop the ppm down, this is my first time with soil so i dont want to starve the plant with just water or will there be enough nutes left in the soil where straight water will be fine

Flushing a soil grow is a fool's errand. It accomplishes nothing.

yea man give em str8 water for a week or so, then nute em up if you wish, adn go back to water for a bit, keep that goin and you should never have to flush unless there is an issue...Peace

Don't do it man. You will only stress them out , only flush if you have over did the nute's man. And then use 3 time's the size of the pot.

I am going to start my next batch with Sunshine #4. From my understanding, it isn't soil. It needs a full reg of nutrients about every other day. Sunshine #4 is a hydro material.