That plant is hungry. In hydro they eat like crazy. Temps need to be 75-78F, RH needs to be 40-60% and ppm >400-700<, EC <.6, Ph 5.8
Check your PPM and Ph everyday. They will eat more water than ferts and your ppm will climb and drop your ph. Just monitor it the res, and keep track of vertical growth. That way you will be able to tell for sure if she is slowing in growth rate. Make sure roots arent slimy.
Yellow= nitrogen hungry
Rusty/Brown= nitrogen burn
If you changed the res yesterday itll prob just need a ph adjust and + H2O later today or tom.