To clarify, I mean that Lowryder 2's, and all associated auto-flowering strains (original LR, master low, powerstout, auto-ak47, etc.) will happily go through their entire life cycle under 18 hours of light a day. Unlike 'normal' cannabis strains, flowering is not triggered by a change in light cycle, rather is just happens after they reach a certain age (usually about 19 days).
So you could start off sowing, say, 4 seeds, and after they'd geminated start them under an HPS or Flourescent tube set to 18 hours on, 6 hours off. At around day 14-17 you check for males and remove (and presumably kill) them. The remaining girls will then start flowering at around day 19 without any change in the light regime.
Around day 30-32, you can then stick another 4 seeds on in the same space. 14-17 days later you remove the males from this new batch, leaving you with two more females. Assuming you got a 50/50 female/male split both times, at this point you have 2 female plants fairly late in flowering, and two just starting to flower. Once you get to day 65 for the first plants, harvest them and use the space you've got back to plant another four seeds.. And so it goes on. Without any need to change light cycle, you can have one area housing multiple plants at different stages of development.
Infact, the only separate area you need is the one for the freshly harvested buds to dry and cure. I'd also advise you not to store any of the fertilizers or other chemical solutions in the grow room under the potentially hot lights, but that's probably obvious.
I would also strongly advise you buy a calender or use a calender program (you might want to use coded phrases if you're worried about stealth) on a computer to keep track of the two different simultaneous grows, or it might get a bit confusing.
The only thing that complicates this setup is if you want seeds when you've got females at two different stages of development, as you need to separate the males or they'll pollinate both sets of females. This does require a separate area for atleast a few days so they can mature and release their pollen, but once that's done, they can be killed and the collected pollen can be applied using one of several methods to your chosen female without fear of them all becoming pollinated.
Hope that helps.
Hi that is interesting i also am tight for space and that if i can manage it will be grate to have a go. This will be my second grow first one turned out to be male from bag seed and i made the mistake of taking cuttings before sexing them I'm a newbie to growing cannabis so its a learning curb and i thoroughly enjoyed it they did root and was happy that i gave it a try.
i is really pissed of with em i got some good genetics as well (or so i thought) greenhouse white widow and lemon skunk and most of them sprouted but not one not even one little green leaf not one fuck it the thing that really pissed me off was that i got some free seeds with then and four out of five live very nicely in deed and they were regular seeds not feminized like the failers i think they were to hard or something?????????
greenhouse 
