Hello folks I'm late 2 this so here goes.growing 2 autos,northern lights,and super skunk,vision seeds,bought from Herbie's,excellent service by the way and def highly recommended. Small tent in spare bedroom,60,60,120cm,bought from Amazon,£50,the black orchid, grt 4 a small grow.both plants in 10 litre pots,canna Terra soil also from Amazon,£10.99 including deliver,fantastic price.250w HP's light.havnt used any nutri's till last week,week 5.they are 6 weeks old 2day,nkp is 8.8.8 and it burnt the plants a bit so flushed yest and won't be using much as autos seem 2 be fine with a good rich soil.as far as air vent goes,no extraction,no carbon filter,don't need it,not a smell and nothing 2 worry about.window is open 4 18 hours during the lights on.18\6.plants are doing fantastic at moment.will get a load of pics up as soon as I can and enjoy people.