Why are these seedlings turning yellow?

[rud3dog]

Im growing blue berry Kush, ak48, UFO's, and white widow clones. Most plants are fine but the ones ion these photos are starting to droop and turn yellow. They are all under a 4 x 4foot mirror reflector with t5's. All the other plants are doing fine. I have grow big, but was worried that it was to late to use it. I will say most plants were planted with fox farm and the rest with um I think its called roots organics which my 4 foot white widows seem to love. Thanks

 

[rud3dog]

I could throw them in the tent but Im using a 600 watt hps 12/12 light cycle for these guys. The first pic is my WW the second image Im not sure WTF it is. The seedling looks differant then all the rest.

I would asume this is blueberry but the rest dont look like this

 

[rud3dog]

mite be ur style of growing,,

Could you be a little more exact? I do 3 weeks under t5's and then veg with MH ten HPS.

I was thinking it was a lack of nutes or somthing.
I got 35 plants/clones growing right now, but I dont wanna lose any and I only have so much room.

 

[tinkerhell]

ive got the same problem! Ive now lowered the PH of my water and given a good glug of bio-bizz-grow plant food..fingers crossed..