GHE is pretty easy to use. GHE flora series. Buy flora gro,flora micro, and flora bloom. Buy calimagic. And GHE web got a pretty easy to follow schedules and amounts. You should start with them now if you want. For the exhaust question! LED lights don't put out that much heat so you could run a test and let your tent reach its max temperature with light on and see how hot it gets of its under 85°f your are good.. of you want an exhaust what I did is I bought a cheap bathroom exhaust fan at homedepot and connect it to the 6in circular window the tent came with that will drop my temperature from 90 that will reach to 82°f i got a 650w LED plus 4 n27 LED bulbs and for an intake I just put a desk fan on another window pushing air into the tent, cheap (under 70$)and works, i don't vent to the outside of my home though. Dark phase during veg keep it to 4 hours when you want to switch to flower just change the schedule I have run an experiment. I once gave her 24hr of darkness when switching and also switched without any dark periods more than the regular 12 hrs.. and there is no difference in how fast it flowers. But the plant with 24hrs of darkness was more pale after I gave her the light again. Once its dark for the plants is better to just leave her in the dark.. of you must check her in the dark tray to do it with a small flash light and do it fast... I got this crazy rule of mine which if I have to check it in the dark I try to do it no more than an hour after lights went off and for no longer than 5 min. But that's me lol. I haven't notice anything abnormal on plants I had checked during dark time though. Hope this helped my friend..
