Thanks all. I guess I should have shared a bit more info when I posted this so here goes. Four plants (3 "CBD Charlotte's Angel Auto" and 1 "Auto Tangerine") each in a 5 gallon fabric pot. Soil only grow using Fox Farms Ocean & Forest with a starter "core" of Fox Farms "Happy Frog". The four pots are centered in a 4X8 grow tent under a "MIGRO 400+" light set on a 20 on, 4 off cycle. One of the "Charlotte's Angel" started showing N deficiency signs (Yellow tips on older leaves, increasing all-over "lime color") at about 38 days. I was slow to pick up on the N as cause thinking I might have a watering issue or pH, since the other three were fine. I gave that one a shot of tomato fertilizer (It's what I had on hand) two days ago and it is greening back up. Onward!! Here's a pic of the one needing fert.