My NPK reading is 1900 what to do

Hi. I'm growing hydro a drip system, I gave nutes 4 days ago and now the NPK reading is 1900. Should I just add water to fix the problem. And most of my leaves are yellow at the edges and curling inside.I'm a week away from harvesting

What medium are you using? If your a week away from harvest I would just dump the rez and use PH'd water only, zero nutes.