Flushing Your Plants

Any advice on flushing your plants? i'm new to hydro system and was looking on some feedback about flushing your plants. When should i flush my plants how often and how to flush them. Any help would be appreciated

Im new at this as well, but ive heard that you should flush them when changing the res water out. Just put pure ph balanced water with no nutes or anything in your res. Then just leave the platns in there for a few hours to a day.... before you add any nutes... but im not expert