Very good advice for the apartment grower here. I have a few more suggestions. If you have a large closet anywhere try to grow there. Heating issues are compensated well with home made drop down ducting from A/C vents into your room. I would use both carbon filter exhaust to another room AND a carbon scrubber inside the room. If you have any decent amount of fear add an ozone generator to that. I recommend the CAP OZN-1 set to a short increment timer. Noise is another issue, so internal rooms, or rooms shared with an outside or preferrably cement wall are the best. As he said invest in a tent. If it is personal use, you can grow all you need in a 2x4 tent, one grow at a time. If you are doing commercial, get 3 tents, a 4x4 for flower, anything small for veg, and anything small for mother(s). Use T5s for veg/mother and a 600W or similar for the 4x4(4x2 also works, but like 6-7 plants max in there). In any case, don't start a ghetto grow in an apartment. You're asking for trouble. Invest a little money, the equipment can be used over and over again, and buying used works great too. With what I know now compared to before, I could get everything mentioned here for around $800-900 used. If you're doing it ghetto start small, get one 400w hps used, a new carbon filter and fan, and the black poly tarp to put over the window of the smallest room/biggest closet you have. Light, odor, sound, and nosy neighbors are your worst enemies and should be the biggest issue.