Can't I flush her with regular tap water
Just make sure you start out with 1/4 strength nutes. That's a problem all of my plants have in the beginning, they always work themselves out in the long run though once they get adjusted to the strength. I don't ever use too many nutes throughout the entire life cycle though, just enough to keep them healthy and strong.
I'm just too lazy to make weaker nutrient water and stronger water too so I just bear seeing them be a little burned in the beginning.