Quite pleased with these........but...

Hello all been reading alot here the past few days but i need a bit of advice.

I don't consider myself a grower in anyway, yet. But i have definitely found myself interested in growing lately. sorry for the longwinded post but its best to explain all first sometimes.

Right
I had 3 seeds of unknown strain. These got put in regular asda compost in the UK's recycling tubs and left in direct sunlight (the little the east coast gets) until around 12 weeks old then they got moved into a light area with direct sunlight for around 6hrs but its still a bright spot after the sun moves around. 1 got pulled as it was Male, 1 got test snipped so as to create 2 buds/cola? and the final one got left as it was. They got water with *ahem Miracle grow every once in a while and just basically left to grow.

The snipped one is about 2 foot high but very bushy and the single is nearly 6 foot but not quite so bushy. They are both 29 days into flowering with no brown pistils yet but the single is doing best, its getting quite dense now and there's absolutely loads of trichomes?, i wish my camera could pick them up, but i have a pic that you can just see them if you zoom a bit (pic- step 5). They stink!

I have 2 slight issues, the small one has 1 or 2 leaves starting to turn purple, and my big one's leaves are turning yellow, all the center leaves are going and its working up the off shoots now. Its happening fairly fast aswell. The nights temps have dropped quite drastically over the past week, could this be a cause?

i have a window in good sunlight most of the day, would it cause more harm than good to bring it inside?

Cheers for reading people, it'd be a shame to see the big one go a such a late stage

edit: all pics are of the big plant, the small one was a test and due to its stunted growth the wife insists on calling it the cute one.

edit2
Pictures are from left to right
1.09.2008
19.9.2008
23.9.2008
29.9.2008
29.9.2008