Discussion in 'Growing Marijuana Indoors' started by superbone420, Oct 29, 2002.

  1. i have exp with out door gorwing trying to get in to the indoor seen i have a 400 watt metal halide 8 buckets 9 squere feet to work with but what i need to no is if my bulb would work its a 400 watt lampe metalarc metal halide halogenues thanx for the help
  2. ....although that doesn't seem like much for the area you are planning to use...
  3. For 9 square feet of growing room you'd need approx 22,500 lumens you're 400w Mh will give you 36,000 lumens, more than anough....Peace out...Sid
  4. sidious,

    would you mind letting me in on the conversion secret? how do you find how many lumens are neccesary for a particular sized room.

    thank you much.
  5. No's on a download i got called cannabis growing guide, by's the bit on lighting, i just done the calculations to get it for 9 square feet, i can e-mail you the whole thing if you want?....Peace out....Sid

    Indoors, 2000 lumens per sq. ft. is about as low as you want to go indoors. If you get under this mark, plant growth will certainly not go as fast as possible, and internode/stem length will increase. Also, light distance to plants will be much more critical. Daily adjustments to the lamps will be necessary, meaning you get no vacations.
    2500 lumens psf should be a good target, and 3000 is optimal if your going to inject or enrich CO2 levels

    Lamp Type Watts Lumens per bulb Total efficiency

    Fluorescent Bulb 40 3000 400 watts = 30k lumens

    Mercury Vapor 175 8000 400 watts = 20k lumens

    Metal Halide 400 36000 400 watts = 36k lumens

    High P. Sodium 400 45000 400 watts = 45k lumens
  6. an easy wat to figure out if your bulbs are enough wattage is for each square foot you need 40 watts for 9 square feet as long as you are at or over 360 watts one more thing you will be needing high presure sodium for the flowering stage

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