I've heard of that stretching thing too but I can't confirm it. I know you always want to keep your temperature difference as low as possible. 66 isn't bad, temps in the 60's help purpling if your strain has that trait.
I would do what comed said and lst multiple plants sideways going the whole way of the attic and use 250 watt HIDs along the apex. Vent inline with a couple fans and have it pull air directly from the outside directly through the lights and directly outside. Then hook another inline fan up to a...
I'm still waiting on plant 1 to come through the soil but the other three sprouted yesterday.
I'm not too worried though because that was the last seed to germinate. If it doesn't sprout over night I'll start germing another seed.
Well your first problem is you need to ph balance your water. It would also help a lot if you knew what kind of soil. Also your going to want more lights if you want it to get bigger.
LST FTW. My last grow I made one plant 3 feet wide and about 1 foot high. It's the plant in the picture. However you can go 12/12 from seed so it's up to you.
I'm not sure what your asking, but I'll throw in my two cents. You can get ph test stuff at a pool supply store. If they are three weeks old your gonna want to get them out of those solo cups soon. I would recommend transplanting into a good know soil like fox farms ocean forest. Just a thought...
You should be fine. I've lst'ed one plant until it was three fit wide. Unless you start breaking branches or something obvious your not really harming it. However you don't want to lst in flower because the plant is trying to produce flowers instead of repairing itself and growing. It would be...
Or you could experiment with LED's in the veg. But if you want something tried and tested, Dr.Manhattan is partially correct. Two 600's in the flowering room and the 400 in veg would be awesome.