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yet another lighting question

Discussion in 'Growing Marijuana Indoors' started by tonyba2014, Feb 5, 2013.

  1. It gets extremely hot though... I'm worried I'll cook them, its a powerful bulb. Should I move it closer?
  2. I added a cfl to the mix, do I need a fan?
  3. Can you grab the bulb without burning your hand? Its gonna be hot, but not unbearable. If you can, then put it, and keep it, less than 1 inch from the top of the plants as they grow. Otherwise, you would usually put no closer than 6 or so inches if It's really hot, like with 100-400W HPS bulbs, but I don't know of many CFL's that aren't upwards of 125W bulbs, being too hot to press up hard to the plants. Even a 200 watt CFL bulb can be put 2 inches from the plants.
  4. I'm talking really hot, like painful to keep your hand close to it. Its one of these.


    Only the second light is a cfl. I forgot what this ones called. The biggest blue grow light home depot carries
  5. #45 aj69420g, Mar 2, 2013
    Last edited by a moderator: Mar 2, 2013
    That looks like a halogen bulb. Most of those have bad spectrums for chlorophyll activity and growth. I wouldnt even use a halogen or incandescent its a waste of power most spectrums say blue grow light, but they are right in the 3000-4000k range which is next to useless. Its just keeping them alive. If you have 20$ go to wal mart, and do what I said above the 48" t12 Fluorescent shop light with 2 bulbs will do a much better job. fixture is 15$ bulbs are 4$ for 2. Each one does around 2000 lumens. so 4k lumens of light would be great. I run two side by side in my grow for vegging. x4 40w 6500k bulbs only running 160watts, 8000 lumens over aa 4 foot by 8 inch spread. all for under 40$
  6. Can I use it with another cfl just for a week or two?
  7. Should I replace it with a second cfl and place it right on top of the cups? And do I need a fan?
  8. Just found these downstairs, I'll replace both lights and get back to you.

  9. #49 aj69420g, Mar 2, 2013
    Last edited by a moderator: Mar 2, 2013
    Ok those 100w replacements should help if they are the 6500k blue color. lookup the bulb on google and see what you can find on the bulb. Those scare me cause they say bright white, that can mean 4200k which again is useless. Most bulb manufacturers go by this standard. Soft white = 2700k and Daylight usually means 6500k whereas yours says bright white. So check it out..
    but to grow all those I'd recommend at least 4-6. Then once they are bigger you will need 3 per plant. its not all about how much light and what color, but the spreads very important too. So CFLs are handy but unless you use a bunch you wont get a good spread. Yes I'd at least get a desk fan and keep part of it blowing on the bulbs and some on the babies.

    1500 lumens is okay but I'd recommend at least 9,000 lumens. meaning get 4 more of those. Idk what spectrums they are but try to get 6500k for veg and 2700s for flower if you didnt already know.
  10. I'll be moving them outside once they sprout, is one cfl for every 4 cups enough?
  11. Not really no, I edited my last post so check it out. for your 12 cups in that dishpan I would do at least 6, 3 bulbs on each side pointing in towards each other horizontally. But if you only had 4 and did 1 in each corner that would work but they will stretch some still.

    The reason is the ones that share a bulb will stretch like a bitch and that can effect alot later in growth with 6 bulb spread you shouldnt get much stretching at all.

    remember that the sides of the cfls have more area of tubing that illuminates. so the sides of your swirls are the brightest part. So putting the side of the bulb 1-3 inches away from the plant will let it get as much as it can
  12. This is what I have until I can hit the home depot tomorrow. Only the six left cups are ganja. The other six are corn.


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