First time growing, need some advice

[Dr-Chronic]

Get pictures up m8

[Bethmeg]

You need to get some extraction going

To run hps lighting in small spaces without extraction is madness.

You might as well put your plants in the oven dear

[clownstyle]

Wow, that's a big stretch!

I've got a similar space, and for two plants the 250w was good. I can't imagine having a 600w in there even in this cold winter.

What temps were you getting inside the space? Hopefully you've got a hygrometer and thermometer to keep an eye on conditions.

Can only really echo what others have said RE extraction. Need a CF now, even if there is no smell you want this setup already before you notice any sort of smell outside of the tent. Good luck