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jon205587

New closet grow setup- need lighting advice

jon205587
15 years ago

Hi everyone,

I'm just getting started into indoor growing and need a bit of advice regarding equipment. Yesterday I got a dual T8 32w fixture and overdrove the each bulb with a separate ballast. It seems to put out a decent amount of extra light with the Phillips Cool White bulbs. I'm going to use this for seedlings and cuttings.

For the main grow area, I have about 3'x4' to work with and I would like to know the best light source for this application. I was considering a 250w MH/HPS combo ballast and the respective bulbs. One thing I was wondering about is heat, since it is in a walk-in closet. Do I need air cooling for a 250w light, or a 400w?

I was thinking of just putting a fan in there and blowing air over the plants to cool them as well as stimulate their growth. Would this work?

Lastly, I've read about the ceramic metal halide lights, and that I should get an electronic ballast. Is this worth it?

Thanks for your help in advance!

-Jon

Comments (9)

  • jon205587
    Original Author
    15 years ago
    last modified: 9 years ago

    I just found a deal on a 400w "floramax HPS" setup with an integrated ballast. Would this generate too much heat in my closet?
    I've included the link (I'm not affiliated with this site)

    Thanks,
    Jon

    Here is a link that might be useful: floramax light

  • jon205587
    Original Author
    15 years ago
    last modified: 9 years ago

    sorry, it was florasun, not floramax!

  • object16
    15 years ago
    last modified: 9 years ago

    Use a remote ballast, use a 400w HPS, a good quality enhanced spectrum hortilux lamp or something like that, and have a small EXHAUST FAN to exhaust the warm air from the closet, and have another intake vent, with another little fan. Use a 4 inch computer style fan with a rating of 30-35 cubic feet per minute, a small quiet fan is all you need. just blowing air over the plants won't do it. your closet temperature will get too high. I use an HPS for all of my mature plant growing needs. seedling and smaller plants are raised nicely under fluorescent. please ignore the "advice" about ceramic metal halide, HPS will grow bigger plants cheaper, unless for some reason you don't like the wierd color from an HPS lamp, and for esthetic reasons you prefer a natural colored lamp, like a cmh. stick with a mainstream tried and true product, that growers like myself have been using for years. and the technology is NOT out of date, modern HPS lamps have MANY improvements over the original lamps that were out 20 years ago. Remember, even a regular HPS lamp is A PIECE OF HIGH TECH EQUIPMENT. you can see my fluorescent garden in flickr, i post threads over in rose propagation forum, and currently my roses are under regular overdriven t8 fluorescent lamps - AND THEY ARE GROWING LIKE THEY'RE ON STEROIDS!!! mY hps garden right now is not growing anything, but when it's in operation, the PLANTS GROW LIKE THEY'RE ON STEROIDS, also!!! furthermore, i don't use hydroponics, just regular pro-mix peat based soil type plant in regular horticultural pots type growing. cheers,
    Paul Mozarowski.

  • lermer
    15 years ago
    last modified: 9 years ago

    Roses happen to prefer HPS light. HPS is not cheaper than
    CMH; they both use the same magnetic ballast, and the
    Philips CMH bulb is way cheaper than the Hortilux HPS.
    There have been no improvements to the HPS bulb since
    Hortilux came out almost 20 years ago. Although now
    electronic ballasts are available for them. What makes
    Hortilux better is not so much the spectrum, but it is a
    higher output (so more blue is produced along with the
    total output).

    Ceramic Metal Halide has been available for about 10
    years, and has been used very successfully by many growers
    for as long. It is the best single light for both stages,
    wtih more blue than an old-style MH and more red than an
    HPS (which is mostly yellow-orange). Often HPS will tend
    to cause premature leaf-yellowing, due to shortage of blue
    spectrum (which induces growth hormones). However you
    could add fluorescent to supplement the HPS spectrum.
    But this would cost more and use more watts.

    With CMH you don't have to change bulbs from veg to bloom.
    The switchable ballasts aren't as efficient in either MH
    or HPS (because only one transformer).

    With Hortilux HPS, with the majority of strains you could
    use for veg also, but with less rapid rooting and more
    stem elongation compared to MH (or CMH). With CMH there
    is more of both red and blue, so it grows and roots fast.
    In the bloom stage, CMH takes a week or two longer to
    finish because the leaves don't turn yellow as fast
    (because of the extra blue) as they usually do under HPS;
    and CMH has more red spectrum (which induces bud
    hormones).

    However the CMH requires a magnetic ballast, if electronic
    you need the low-frequency Ultra-Max made by GE.

    Usually CMH will yield about 50% more than HPS, if you
    have plants less than 2.5' tall and with most srains.
    Roses are the exception.

  • lermer
    15 years ago
    last modified: 9 years ago

    The 4" axial fans Paul talked about tend to be very loud.
    The smaller the fan blades, the faster they have to go and
    so are less efficient. The easiest, cheapest way to vent
    your closet would be to leave it open while the lights are
    on, with a 16" pedastal-mount fan from Home Depot (costing
    about $25) blowing in. Otherwise you need to cut holes in
    your door and put up with the the high-pitched whine of the
    small fans. If you do cut holes in your door and mount
    fans, I recommend larger fans like squirrel-cage which
    have an advantage over axial in that they do not allow
    light to pass through and potentially interfere with the
    photoperiod (usually flowering requires 12 hours darkness).
    Probably you want squirrel cage fans in the range of about
    200cfm.

    400w would result in more yield and costs the same as 250w.
    That is, assuming you have adequate ventilation to
    maintain a temperature of 76F.

  • object16
    15 years ago
    last modified: 9 years ago

    Because PHOTOSYNTHESIS IS OPTIMUM at 70-85 degrees. Once the temperatures rise, plant breakdown takes place and photosynthesis is not as efficient. Even though the plant might grow, IT WILL BE UNDER VERY HIGH STRESS, some plants, for example even cannabis, not that I grow cannabis mind you, but if you have a nice female plant with abundant large blooms, and your closet gets too hot, the female plant will sprout male flowers, due to stress, pollinate herself, and instead of a nice large female flower rich in resin, you have a pollinated female rich in seeds, which is good if you're growing for seeds, but not good if you're growing flowers.

  • lermer
    15 years ago
    last modified: 9 years ago

    Squirel cage fans block the light, an important
    consideration if some plants need 12 hours of darkness to
    bloom. The axial fans Paul is talking about do not block
    the light; you would have to rig up something else to do
    that.

    The axial fans that are quiet, tend to have low cfm.
    Because small axial fan blades have so little surface area,
    they need to rotate fast in order to move a lot of air.

    (Paul) " Electrical and computer fans at low rpm are
    virtually silent,..."

    (Lermer) "Electrical" fans? I had thought all fans were
    electrical, although I suppose there might be little elves
    with hand-powered fans.

    "Computer" fans? I don't know what kind of fan Paul has,
    (perhaps the original WWII-era Eniac); but in all the
    computers I have seen, the axial fans in them are too
    small to be useful for plant room ventilation.

    (Dcarch) "The computer type of cooling fan is specifically
    designed for ventilating and cooling."

    (Lermer) Silly me, I had thought all fans were for the
    purpose of ventilation and cooling. Please, tell me where
    I could get some fans that are not. Ripley's Believe it or
    Not might be interested.

    (dcarch) "Squirrel cage (centrifugal) blowers are
    specifically used to overcome backpressure situations as
    in pushing air thru ductworks. It is never used for
    general cooling purposes."

    (Lermer) Squirrel cage fans have that capability, but they
    don't have to be used in ducting; in fact they are rated
    for different lengths of ducting starting with none at
    all. Normally I wouldn't use them without ducting (because
    of the higher cost) but they do block the light. If you
    read what I said, my first preference was for an open door
    with a 16" pedestal mount fan from Home Depot. Telling
    someone to make holes in their door and install axial fans
    in them, without warning them about light leaks (in and
    out) is irresponsible.

    (dcarch) "Before you use a 16" fan to blow on your
    seedlings, say goodbye to them first."

    (Lermer) I said, pedestal mount; which means, the height
    is adjustable. Jon didn't say anything about seedlings.
    Those can be placed away from strong air currents. The
    bigger plants would appreciate the air movement (as any
    but rookie growers know).

    (Object 16) "PHOTOSYNTHESIS IS OPTIMUM at 70-85 degrees."

    (Lermer) That's an incredibly ignorant statement. Where
    did you hear that? Generally, he optimum temperature is
    76F. For every two degrees above that, you lose about 10%
    of the plant growth. This isn't apparent to the naked eye,
    except at extremely high levels. Above 76F you will see
    more green leaves because the leaf surface area increases
    (leaves become thinner) to transpire/cool more; and the
    leaves at such high temperatures tend to be more full of
    water. Once you weigh the dried mass, you will significant
    reductions in yield at 85F. Although light-on periods
    should have at least 70F.

    http://www.umass.edu/umext/floriculture/fact_sheets/greenh
    use_management/gh_cool_growing.htm
    "For many crops, media temperatures for germination should
    be between 72F and 76F. After a crop is established, most
    plants will tolerate non-optimal temperatures more easily.
    Seed germination is not the place to skimp on heat."

    (Lermer) Adult plants can usually tolerate slightly lower
    or higher temperatures, depending on species (where they
    evolved). A few degrees above optimum is a lot more
    harmful than a few degrees below optimum.

    (Object 16) "Plant growth is mainly a function of total
    number of photons - a rough measure of light intensity is
    lumens, so have a look at both lamps, and decide whether
    one or the other has sufficient lumens."

    (Lermer) "Lumens" is a "rough" measure, true; very rough,
    because it is biased toward the center of the spectrum.
    HPS reads very high in lumens because it is mostly yellow
    spectrum. However lacking a better common
    measurement, "lumens" is a factor to consider; but you
    should also consider spectrum. Generally you want a full
    spectrum, between 400-700nm, blue (about 420nm) and red
    (about 675nm) are the most important. For that, CRI (color
    rendering index) is a rough measure.

  • jon205587
    Original Author
    15 years ago
    last modified: 9 years ago

    Well I decided to get more overdriven T8's since I can get a fixture/e-ballast for $8.50 at home depot. I got 10 of them to make 5 overdriven 2x T8 lights. Now I've got about 50,000 lumens, I hope its enough for growing tropical type plants.

    Any advice on how to mount these things? I was thinking on a 2x4 fixture I build a few inches apart and putting some mylar behind it and on the sides for reflecting.

    Also, I got a 10 pack of Phillips 6500K 32w T8 bulbs to use. Should I get some soft whites to supplement during flowering? The CRI of the 6500K is only 85.

    Thanks,
    Jon

  • jihar08
    12 years ago
    last modified: 9 years ago

    Sounds great!

    Details are incredibly important when growing your own plants. Creating the perfect environment and grow space is incredibly difficult because there are so many different factors involved. Measuring the room, airflow, watering systems, temperature, humidity, filtration, nuitrient balance, pH levels, Searching for perfectly air-cooled lights, cross air ventilation, an optimal hydroponics system, having it be fully automated, properly air-filtered, light tight, with door lock and key, that has "infra-cool" cabinets that are cool to the touch along with a beautiful clean look and quality and the thousand other variables is extremely time consuming and downright expensive.

    Here is a link that might be useful: sliding closet doors for bedrooms