what do i need to do

one of my plants have really dark green vaines on top 2 leaves and r sort of curling inward what should i do or what is this caused from?

You're probably overfeeding it.
Hard to tell without a picture.

npk 20 20 20 i only water once a week with fert and mist 2 times a day with water not over watering or under green and curling edges with almost looks blue vains