to start off there is that question if you have 400watt hps vs 2 200watt cfls which one is better? another question is my closet is small and is only about 2ft deep, so could a 400watt hps go in there and not start a fire ? also because it is very cramped when they are flowering which light has the best penetration, so you can get buds not just on the top layer? this question is jumping ahead a bit, but i think the two cfl bulbs will have better penetrating power. i also think that the hps if there the same wattage is better. i currently am using a 250watt cfl, so if i brought another 250watt cfl would this be better or a 400 watt hps work better . i know none of what i think in the above paragraph is accurate its just my guess. thank you for any help on the issue.
The 400W is an HID, high intensity discharge, more powerful than a CFL. Yes, it could go in a 2 foot deep space, but you will need some good ventilation. CFL's penetration length is just a few inches, HID's are more, but bottom line is you want whatever light you use as close as possible without causing heat stress.
It really depends on what stage you are in and how many plants you are growing. If you are only growing 1 or 2 plants, then you can even get away with 1 250W bulb. If you are vegging, I would say use the CFL if they are the correct spectrum. HPS does a pretty crappy job of vegging unless you have a full spectrum bulb. The other advantage to CFLs is less heat generated. A 400W HPS kicks off a hell of a lot of heat. In a small grow area that can be a problem without proper ventalation. Hope this helps. Good luck.
alot of hydroponic stores sell "full Spectrum" CFL's, and MH's. the full spectrum is great for the vegging stage, and can also be used for flowering/budding, but its probably better off getting a red spectrum bulb the 27k. If you buy a reflector made with a fan duct in it, that would help keep the light bulb (hps/mh's get hot) cooler, and also put a oscilating fan in the space to help regulate tempature, or even yet if you have a window unite A.C. use that to help keep the correct tempature. but ive seen alot of people grow very nice lants with cfl's, they mosstly used a combo of 2700k/6400k together, which would be great because one is for veg one is for bud/flower
alright my space is 21 by 45 inches, so its smaller than 2 feet. as for ventilation at the moment i haven't got any. i added a vent on my closet door for night time and during the day i leave the door half open. it is only a meter away from the window, which i leave open most the time. temperatures during the summer where great it stayed around 27, but now during winter it is around 17 to 14 degrees. i don't want to add a heater so i thought the hps would heat it nicely but during the summer time i might revert back to cfls and buy that other 250watt cfl as well. i don't mind buying the hps now and another cfl in a couple of months. i am using the right spectrum for both stages at the moment but the veg one is only 150watt bulb. i don't have an a/c unit and i really dont want to cut holes for the ventilation i have looked in to all of that but with my current situation i would rather not. i may move the whole operation into the loft in about a year or 2 but that needs a lot of work before that will ever happen, so for the foreseeable future its my closet. i am a big smoker so i am looking for a nice yield thats why i cram them in there i currently have 6 plants in there but thats because 2 where males. so i fit 8 plants with 11 liter pots i have got a fan in there as well but i made sure that wasn't taking up any precious floor space any opinions would be much appreciated. thank you