First grow advice

Hi everybody!

I have my first grow in progress...

I was sort-of surprised how well all of my seeds germinated but due to space I had to choose the best looking germ'd seeds and have ended up with 4 baby plants.

They are all around 3 weeks old now and I had some issues with them "stretching" but after forum advice, have buried them and they seem to have thanked me for it. Now almost daily they are showing signs of new leaves emerging. (I should probably mention, I literally dug some mud out of my garden and went ahead (lol) ) It's all been a bit of an experiment but they seem to be growing quite nicely by the windowsill and have decided to invest and try my hand at "indoor gardening" so will be transferring them to a better space soon.

I have a spare cupboard I am planning transferring them to once my lights arrive

The cupboard is around 6 ft high, 3 ft wide and about 1 ft deep.
The lights are 600 watt "Lumii" Dual Spectrum HPS
(It came as a kit with an inbuilt 18/6 and 12/12 timer setting on the power box thing)

I am trying to do everything on as small a budget as possible but what other essentials am I going to need apart from: larger pots, a tray for them to sit in.

I know you can get very technical with it all, especially in hydro/etc. set ups but will I definitely need to buy nutrients and possible more?

(I will post pictures once I have my cupboard setup and lights arrive)

edit:

Forgot to mention I will obviously need to do something about smell once they start to flower, what is the stealthiest, cheapest option for eliminating odour? - I have read Ozone generators work well but don't really understand them but if they do the trick!
(I'd also prefer not to have huge silver piping laying around, if I can avoid it)

Also, I have read many times CO2 can help yield much greater grows, what are my options on helping my plants breathe

edit 2:

would this sort of thing aid with smell?
http://www.ebay.co.uk/itm/PLUG-IN-O...005&prg=9701&rk=3&rkt=6&sd=141193418507&rt=nc

Look to upgrading to a tent in time, dealing with stink this late shows bad planning on your part, and C02 can be as easy as letting you stale breathe mist over them, as you sleep, deal with your excessive temps before concerning yourself with C02, look to making your own DIY filter and add 2 small pc type fans

Hey vostok, As I said, it was all a bit of an experiment that has started off well anyway..
I was considering a tent but due to the small depth of the cupboard wasn't sure about it but I will definitely have a look around for one that would fit. I totally forgot about fans/temps when posting before, I have some USB fans spare I was planning to use but still thinking of a way to power them inside the cupboard without a comp/laptop being in there too and on 24/7.
If not I will pick up a few cheap desk fans of something similar - and for checking temperatures I was considering one online, again cheap and cheerful but if it does the job!