light green edges on leaves?

This little girl is about 3 months old, she is on a 18/6 light cycle housed with some others under 6 100w replacement 6500k cfls. I water every other day and add nutes 2/wk. The edges of the leaves, even new growth, have started to turn light green. First time grower, any idea what this could be?

u have given the plant too much nutes

So should I flush and how exactly do I do that?

well u need alottaaa water bro no foood juss water, and dont flood the soil; no puddles on the surface an shit have good air and hope for the best!

Just water... no nutes... maybe even get a water/ph/light meter... I use this one ($7)