Is 400W hps too much?

Discussion in 'Growing Marijuana Indoors' started by rooster1369, Jan 17, 2009.

  1. I'm building my own grow cab. It's 32"w X 21"d X 58"h. I think that's about 28 cubic feet. I have a 25cfm fan blowing in at plant level and a 25 cfm fan blowing out the top. I'm thinking of getting a 400w hps/mh combo from Sunlight Sheds. It comes with an inline air cooled reflector and a 115cfm fan. Will I have heat issues. It seems like it's a lot of light for that space. My last grow was cfl, it was kind smoke but the plants didn't produce much. All ideas are helpful. I'm still in the building stage of my tent so a little design change would be easy. :confused_2:

  2. My cab is 32x22x60 so it's just a few inches larger and I'm using a 400watt bulb. I'd like to get a 600 actually. I don't know the temperature in my cab but I've only got light burn once and that was before I put a fan in. I don't even have any ventilation yet. Truly a budget grow.

    If you've already got ventilation and fan's, I'd get a 600 watt. I'm have slight light penetration issues. But then again I had 6 plants, and only just today went down to 5 (1 hermied out)
  3. Not really such thing as too much, not with 400w. I say go for it, but put everything together BEFORE growing. See what the temps are like before you have plants that will get cooked. My cab (3x3x5) got up to ~95* with no ventilation. I'm using a 500cfm 8" fan from Home Depot for the light, and another for the carbon scrubber. The cab stays 65-80 at most, it varies with the outdoor temp but is usually right around 70-75. I can leave the back of my hand on the pane of glass under the HPS bulb and it's just barely uncomfortably warm. You can always add more ventilation to keep the grow cool, just as long as you make sure everything works before getting started you should be fine
  4. Thanks, I'll look into the six hundred.
  5. Haha I'll make ya a deal. Buy me the 600 and you can have my 400 watter :)
  6. I think Ill just get the 600 now and not get myself in your predicament.
  7. Thanks for the tip on running it first ZPYRO. The 600w just $50 more. Can anybody give me a good reason not to buy? I can always add another exhaust fan.
  8. Get the 600w. There is no such thing as too much light with good enough ventilation, but your electricity bill will go up.
  9. I think I'm gonna go with the 600w and use the 115cfm fan that comes with the light to vent my cab and get a 250cfm inline for the light. That's almost four air exchanges a minute. I don't think there should be any heat issues. Should the fan be blowing into the light or sucking air across the light? Thanks for the help guys.:bongin:
  10. the 600w is 50% more than the 400w so it will go up, but probably not enough to really make a difference. if you haven't already, change all of your household bulbs to CFLs, you'll probably end up using less power if you do that, even with the 600w

    Can't think of a good reason, really. I plan on upgrading my 400w to a 600w when I have the $. I went with the 400w because of the size of the cab, but the extra light definitely won't hurt anything. If anything I can just duct the light hood to cold outside air (right now it's just sucking the closet/room air, if I run the duct so it goes outside instead I'll be bringing in colder air because I have the light on at night) if heat is an issue. As long as you ventilate the light and cab and you have plenty of airflow inside the cab you shouldn't have any issues

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