Its dying now

This is my first grow so im kina upset looks like I might lose my L.A. I Transplanted Used kellog patio plus soil and and fed it flora nova grow once and my l.a. looks like it didnt like it to well. Heres some pics of what I started with and where im at now Im using a Grow Tent for lighting I have A 400watt hps running 24/0 im thinking of switching to my 600 for flowering but im not sure if I should.

Heres a few more pics I hope I can save the La. The other bushy one to the right is a sugar babe and the two in the back of my grow room are purple haze they seem to be turning yellow. Im hoping if I dont feed them any more flora nova they will get better I need some help with this if anybody knows what I should do. Oh and the reason I fed them the flora nova was cause I was using it before the transplant.

My guess would be heat stress, lights too close. I've done that a couple of times.

The light is about 18 inches from the tops of the tallest plant I thought that should be enough? This plants Were started at diffrent times the purple haze was from clones that were planted in late october the la was from seed planted in november and I started the surgar babe again in mid november im now watering every three days. Could heat stress be caused by the temps alternating to much in the grow area?