Maybe to hot?

Not sure what happened here i thought it could of been the temp was up over 90 for a couple days but i got a new exaust working good now......maybe its under fertilized or something i havent fed it anything and they are 5 weeks old it seemed to get worse you can see the different pics are dif colour ....taken a week earlier so if anybody has seen this before let me know?!!!! i have 8 24w cfl's in a 2x2x4 space with a fan blowing and a 50 cfm exaust fan so i cant see it over heating maybe ill add some nutes to the water....also the stems on the one plant are purple along with the edges of the new leaves at the top....they are all light lime green with a bit of purple so anyway any suggestions are better than none im willing to try anything that wont worsen the prob....thanx peace

yeah a little too hot i have same problem temps around 91 but its all good dont worry about it. it could be nutes also. feed them temps usually fuck em up worse check my grow out on this one day it went crazy orange

If you're not doing it already, I'd be adding 1/4 tsp of Epsom Salt (Magnesium Sulfate) to every gallon of water you use. Even if it's not Mag deficiency this time, it could creep up on you.

looks like it cud do wth a feed u can tel by the all round yellowness on the leaves
dunno maybe im wrong

ya i gave it a nice feed and its come back to dark green looking better should i be feeding a fert like 20-16-10 half strength or a 10-6-8 or somethin...thanx for tha advice though it seems to be working

This was definatly a feeding issue i had it happen again recently but i caught it early and recognized the signs so i guess better under fert than over fert.....keep it green