first grow in coco....small problem

hey guys, heres a list of my setup

2x 250 watt cfl's
canna coco
canna a + b
3x annapurna super autos
1x number 1 super auto
temp sits around 80
humidity around 40
water ph'd to 6 - 6.5

the seeds got mixed up in germination but im pretty sure i know what is the number 1, this is the problem one i think, anyway one of the plants that i have the edges have started to curl up and starting to brown, i think its the number 1 that is doing it cause the other 3 are fine and this ones seems to be growing quicker, they are about 2 weeks old, i rotate the plants every day or two for even light i gave them a very light dose of a + b 4 days ago

so what do you think the problem is? maybe the number one is just sensitive to the nutes since they are still young? im not sure thats why i have sked everyone here at RIU



the one closest in pic one is the problem plant, and all other pics are of the same plant, picture 1 is from a few days ago so the plants have moved around one position since then, thats why in the other pics the problem plant is sitting at the back and not the front













thanks for looking


and one more question, am i suppose to use normal nutes with canna a + b

anyone got anything to say?

c'mon guys the problems not getting any better, need some help fast