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How many lumens in a 4x4 tent

Discussion in 'Lighting' started by TaylorAppleseed, Aug 29, 2010.

  1. Hello GC,

    I've been researching on growing for months now and this will be my first grow. I will start in about 2 months. So right now I'm trying to order my growing set-up. I pretty much know everything I will need but a little confused on how many lumens i'm going to need for my veg tent that will be 4x4. I plan to use T5 lights for the veg tent and HPS for the flower tent.

    I plan to have 6 plants around 2ft tall in the veg tent. How many lumens will I need to grow to this height? They will be in 3 or 5 gallon pots.
    I was guessing around 30,000 lumens.

    I have searched around and just couldn't get a straight answer, thanks for any help.
  2. id go with one 1000 watt, im in a tent thats 2x4x7, its not growing yet as im still piecing my setup together. and from what I read its not always about space that dictates amount of light needed, I've read on several occasions you want a MIN of 100 watts per plant, so if your doing 6 in a 1000 watt setup, your plants will definitely be happy with their light supply. You will probably need an air cooled reflector though, I ran test in my tent without ventilation and it got to about 120 with mh and around 109 with hps, I should be in the ok when I have it setup completely.
  3. Well I'm trying to get a close figure to how much light I will approximately need, due to energy waste. I'm going to have 2 veg tents and one big flower room with a 1000w HPS.
    The energy of running 2500watts all day would be outrageous and look suspicious.
    That's why I was going with some T5's.
  4. I have been able to provide decent vegetative growth with two 4'-4Bulb t5 units in a 4x4 tent that came to 40,000 lumens. But since one can get much better results with HID lighting, I added a 1000W HPS to the mix(145,000 lumens) bringing the grand total to 195,000 lumens in the 4x4. The HPS made a huge difference and basically over powered the T5s so I decided just to use them for my mothers and clones. With decent light distribution, the 1000W HPS in the tent will provide excellent vegetative and flower growth.
  5. Hey thanks for posting!

    Hmm looks like I may want to forget about the electricity cost and go with some HID's.
    What are the advantages of using a HPS for veg over a MH? I thought MH work best for veg growing.
  6. If I'm going to need 40,000 minimum lumens from a T5(from what i've seen this is true) using 8 bulbs that is nearly 440 watts. I can get 95,000 lumens from a 600w HPS bulb.
    Still unsure if the HPS over MH is the way to go for the veg tent though.
  7. MH seems to emulate earlier season sunlight, whereas HPS emulates late season light with its red spectrum. There is no one way to do it, at least I haven't seen one. Myself and many other growers, such as Ed Rosenthal use HPS for veg and flower. Some folks use MH for veg and HPS for flower and swear by it. I am in no way stating that they are wrong by any means, just that I prefer HPS the entire time.

    The only real way (that I know of) to see what color temperature will provide the most photosynthesis is to make a solution with a decent size sample of leaves from your plant and ethyl alcohol, then use a photospectrometer to determine what wavelength reacts most to the solution. Then choose a lamp that is closest in color temperature to that wavelength. Unfortunately, this can change over time and will require multiple lamps at different color temperatures to go by it the entire grow. With enough money to burn, I would love to try this.

    Also, that method would require a pretty expensive machine or access to a decent biology lab that doesn't mind you bringing in cannabis leaves for testing lol.
  8. @DrTrichome

    Aw just like everything else in marijuana growing, there are multiple ways to do it, and no one best way ( so to speak).

    Both sound fine but I think I will try out the HPS. Thanks again :D
  9. Good call man. Let us know how it works for you. Peace

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