you would have to have a separate bin/flood table to achieve a proper flush. in your grow how do you keep all the same plants on one table while adding new ones in? every time i begin to flower a vegged plant i have to ease up on my ppms or i fry the roots with bloom nutes, then i gradually increase once a week on rez changes. but anyways for a good flush your going to have to build some buckets or something and create something so your plants have a supply of its own fresh water for a week to flush out the nutes. flushing once dont do anything but get rid of some of the salts, but flushing it a week will allow every nute to be used up in the root system and the plant itself.