One has yellow tops despite the exact same conditions

My second grow
I have two (GreenHouse Seeds Cheese) with the exact same soil, amount of perlite, amount of vermiculite, PH, fertilizers, ppm, amount of water, and so on

But one of them is just growing slower than the other one and is yellowing quite a bit now & has no pistils yet as the other one got for about 4 days ago

Is this lack of nitrogen?

Picture 1 is the problem plant
Picture 2 is the one that is doing perfect and has started to flower

And is 3.5 gollon pots to small for 25.2 inches plants?

Nitrogen issues start at the bottom of the plant. I see a bit of that here, but nothing serious at all. The tops of the plants don't look like N def at all.

Compare to these pics to hone in a bit:

http://www.growweedeasy.com/marijuana-symptoms-pictures

I try not to give diagnosis of plants without being there in person, so hopefully someone who has experienced your issue before will speak up.

-spek

spek9 said:

Nitrogen issues start at the bottom of the plant.

Click to expand...

I forgot that yeah, i think the leafs looks very odd, and i can't find any picture that look like the same problem anywhere

- Some of the small/new leaves is also deforming on the yellowing plant (only at the main top)