Auto plant not flowering yet

[Swedge]

So my seeds sprouted on 7th October so I'm about 7/8 weeks in my picture my auto ak47 is on the right which started flowering a couple weeks ago and is doing fine

The plant on the left is pink diesel/amnesia

Sprouted about the same day and always looked more in front than the ak but it's still not flowering yet

I'm getting some yellow leaves on the bottom and had some nute burn but that's gone now

I'm running 20/4 cycle under a 600hps with some cfl side lighting

Any ideas?

 

[theengineer]

are you sure it's an auto, and not a photo?

 

[Swedge]

Yeah they were both sold as autos the pink diesel amnesia was actually a free seed but they do say it's an auto

 

[Swedge]

I could change the lights to 12/12 but would that not be bad for the ak who is doing fine

 

[theengineer]

I ran 90% of my autos on 12/12, so it won't harm them at all

 

[Swedge]

This is from the non flowering plant

 

[Swedge]

Still no sign of flowering

 

[Paint]

The first auto I attempted to grow took along time (7 weeks) to show its sex too, it was a Afghan Kush Ryder auto fem which actually turned out to be a male plant! I thought that might have been why it took longer to flower maybe??? Just another thought....