t8 light bulb for growing?

Discussion in 'Lighting' started by ganjahillbilly, Nov 24, 2011.

  1. looking for any info on an all glass aquarium rapid start 32 watt light bulb. its a 48" bulb i used it last year to start plants from seed it seemed to work ok. this year i wana use it plus 6 cfl bulbs to grow autoflowering plants inside. any ideas on what the kelvin rating on this bulb is?:smoke:
  2. Back in the 1970's all we had was 4 foot flouros, cool white for veg and warm white for bloom, both 48" tubes thru out 3350 Lumens each, that is still more than your average 23w cfl bulb at last count was a pitiful 1500 lumens, but because they are smaller you can get them right to the leaf, where as with the tube you got to use books to get them up to the light during seedling stage, months later some guy stole a street light, so now we bloom under them in the form of hps lighting...easy

    a pic of your 32w would be nice

    man its all in the lumens

  3. Ganjahillbilly: please let me cast a second vote for T'5's. (There's no sinner like a reformed sinner). I switched to T-5's a year ago and haven't looked back since. The manufacturers have done a lot for us. We have good vegging and flowering tubes and the only stipulation I would make is to be sure it's big enough to cover all your grow. If you have a fixture with four lamps two feet long that's as much as it will illuminate with the intensity you need. Nothing beyond that.

    A friend who uses HID can light a grow a couple of feet wider and longer than his fixture but it generates a lot of heat and he has an electric bill that looks like the national debt. You can set your T-5's down to an inch or two off the tops of your plants but he can't. I think you'll be happy with T-5's and they're cheap to run. I hope this helps. Hank
  4. thanks for all the help this is gona be my first inside grow im trying to do it with what i have on hand to see if i can actually do it. if it works the first time i am gona invest in an all t5 set up 48" up top and 12" on sides and 18" on back wall my box is 66"longx42"highx20"deep all gloss white paint inside.
  5. #6 Hank Alvarez, Nov 26, 2011
    Last edited by a moderator: Nov 26, 2011
    Ganjahillbilly: As I read it, if your box is 20" deep and 66" long and you're going to have a lot of room left over. Those aren't dimensions conducive with the manufactured sizes of T-5 fixtures. They come in lengths of 2' and 4'. You might want to look into a fixture with six or eight tubes wide to cover the entire depth of your growing area. You won't find anything the length of you space so that's what I mean about you having space left over.

    Essentially, if you buy a six or eight tube fixture four feet long, and you'll have to measure the width of the fixture, you'll be buying two narrower ones in one. It'll be initially more expensive but I think that's a lot better than having multiple fixtures and hangars. I like the idea of having to hang and adjust only one fixture rather than the two fixtures like I have now.

    My only regret is that I didn't buy the wider fixture to start with because that would have covered my whole growing area. I was on a budget trying to cut corners so I bought the four tube model. My four tube fixture is only about 14 or 15 inches wide.

    That width does a good job on two 10" by 20" starter trays set long ways end to end underneath it or over my two 14" wide bubble tubs set end to end. But I can't effectively illuminate anything wider/deeper or longer than the size of my fixture. The four feet length is perfect for the width of my tent but a wider six or probably eight tube fixture would cover the two feet depth of my tent. So do your careful measuring first.

    Next time around I won't be penny wise and pound foolish, I'll buy a six or probably an eight tube fixture four feet long to light up the entire growing area of my tent. With six plants in my two tubs under my four tube fixture they get crowded and grow out of the depth area of my light light to the reflective sides. The parts of the plants on the fringes of the light are weaker and less productive than what's right underneath. It'll literally double my growing space if I do it right next time.

    The problem with florescent lighting is that you have to have the light directly above your plants and illuminating all of the plant area or the ones at the fringes will get scrawny and less productive stretching up to the light. The ones directly below the fixture are fine. I hope this helps because I know I would have liked to have known this while I was shopping. Hank
  6. 4’ Linear Fluorescent Bulbs\tLumen Output
    28 Watt T5 \t 2900 lumens
    54 Watt T5\t 5000 lumens
    25 Watt T8\t 2209 lumens
    32 Watt T8\t 2850-3100 lumens
    34 Watt T12\t 1930-2800 lumens
    40 Watt T12\t 1980-3300 lumens

    from here: Fluorescent-lamp formats - Wikipedia, the free encyclopedia

    Don't forget...it's all in the lumens

  7. T5's come in 2', 4', 6' and 8'.

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