IS this enough Light

Hi I have two 75 watt fluorescent grow lights and Im just wondering if this will be enough light for three plants at a time. Please Respond

you need atleast 1 100w equiv cfl per plant for veg imo the more you have the better just try to keep the heat down with good air flow

watts aren't what matters, thats the power consumption, you need to be looking at lumens, add them together from the bulbs, and divide that by the amount of sq ft (LxW), anywhere from 7k-10k/sq ft is good

what kinda lights reg. floro tubes or cfls? if u have 150 watts of actual cfl power then yeah you can grow 3 small ass plants from start to finish. dont veg too long, and make a lil grow box with lots of reflective material

Thanks ya I have a small grow room made completely of mylar with a fan blowing in and a fan blowing out. Also I cut down to just two plants they were planted on 7/5/09 and they are about 5inches tall and lime green. The soil is 3month feed miracle grow

and by the way the lights are CFL's Im thinking about buying one more light Im starting 18/6 light cycle tonight they have been on 24 hour hopefully everything goes well

Mattplusness said:

watts aren't what matters, thats the power consumption, you need to be looking at lumens, add them together from the bulbs, and divide that by the amount of sq ft (LxW), anywhere from 7k-10k/sq ft is good

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Actually, watts is what matters. PPFD(photosynthetic photon flux density) is often measured in µEinsteins, or as most call µmol(over time and area). Or simply in watts. Lumens don't mean shit except when comparing, basically, identical bulbs.

But nice try.

Also, lm/sq ft, again, only means shit when comparing the same bulbs. For HPS you need a much higher lm/sq ft than MH, or fluoros, as these two types produce a much higher density of PAR(photosynthetic active radiation) for the amount of lumens produced.

is 400 watt metal halide big eneough for a room? Room is2.1 meteres square

TeaTreeOil said:

Actually, watts is what matters. PPFD(photosynthetic photon flux density) is often measured in µEinsteins, or as most call µmol(over time and area). Or simply in watts. Lumens don't mean shit except when comparing, basically, identical bulbs.

But nice try.

Also, lm/sq ft, again, only means shit when comparing the same bulbs. For HPS you need a much higher lm/sq ft than MH, or fluoros, as these two types produce a much higher density of PAR(photosynthetic active radiation) for the amount of lumens produced.

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No. Usually Lumens and Watts roll proportional to one another (higher watts usually means higher lumens). Lumens refers to the power of light. Watts refers to energy conversion - Electrical Energy (from your wall) to Light Energy. Lumens are what matter to plants, Watts are what matter to your wallet.

Iron Lion Zion said:

No. Usually Lumens and Watts roll proportional to one another (higher watts usually means higher lumens). Lumens refers to the power of light. Watts refers to energy conversion - Electrical Energy (from your wall) to Light Energy. Lumens are what matter to plants, Watts are what matter to your wallet.

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Do you think my my room will grow good then with what I have going.

Iron Lion Zion said:

No. Usually Lumens and Watts roll proportional to one another (higher watts usually means higher lumens).
HID, and the standard incandescent bulbs increase lumen to watt ratio as the total wattage is increased. Fluorescents do the opposite.
Lumens refers to the power of light.
Lumens refers to the "'power of light' as perceived by a human's eyeball". Highly based on greenish-yellow intensity light. Plants love blue and red light. They reflect green light, as they appear green. Objects absorb colors they don't appear as. And reflect colors they do appear as. Thus why we see them as their color.
Watts refers to energy conversion - Electrical Energy (from your wall) to Light Energy.
Close, luminous efficiency refers to the actual energy conversion the lumens per wat(lpw or lm/W)/ Lumens are what matter to plants
No.
, Watts are what matter to your wallet.

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Wow! You really don't know what you're talking about. My comments in bold, of course.

A high lumen rating may or may not be desirable. The best plant-specific bulbs output lower total lx(lumen) and lower CRI than your typical indoor/outdoor lights, typically designed for high CRI or high output.

PPFD/PAR/PUR/etc. is what matters to plants. Read a book, go to your local library or something. This information isn't hard to find.

Lux(lumen flux) does not equal PPFD. Not even close.

TeaTreeOil said:

Wow! You really don't know what you're talking about. My comments in bold, of course.

A high lumen rating may or may not be desirable. The best plant-specific bulbs output lower total lx(lumen) and lower CRI than your typical indoor/outdoor lights, typically designed for high CRI or high output.

PPFD/PAR/PUR/etc. is what matters to plants. Read a book, go to your local library or something. This information isn't hard to find.

Lux(lumen flux) does not equal PPFD. Not even close.

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Ya I'm pretty sure I know what hes talking about, just goto home depot and look at the rack of phillips floro tubes. Take the green plant one lets say the 2 ft, its 20 watts and puts out 400 lumens but the 2' bright white puts out 700 lumens and is still 20 watts.

TeaTreeOil said:

Wow! You really don't know what you're talking about. My comments in bold, of course.

A high lumen rating may or may not be desirable. The best plant-specific bulbs output lower total lx(lumen) and lower CRI than your typical indoor/outdoor lights, typically designed for high CRI or high output.

PPFD/PAR/PUR/etc. is what matters to plants. Read a book, go to your local library or something. This information isn't hard to find.

Lux(lumen flux) does not equal PPFD. Not even close.

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Enlighten me, what should I be looking for in a light? If I want to keep it to CFLs if possible. Grow room size 50cm*50cm*100cm, probably 3-4 plants in 3 gal soil containers. Thank you.

Cant remember who it was but someone showed me that you take a powerstrip and get light socket adapters that plug into an outlet and plug in 68w CFL's the biggest CFL ive ever seen. Then you can put the lights where ever you want and it will only cost like 80 for plenty of light

shkim4 said:

Enlighten me, what should I be looking for in a light? If I want to keep it to CFLs if possible. Grow room size 50cm*50cm*100cm, probably 3-4 plants in 3 gal soil containers. Thank you.

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Unless you can find PURple CFLs, strip fluoros(T8s) are the best. Better than T5's, unless you can find a plant-specific bulb. But none of the major manufacturers(GE, Sylvania, Phillips) apparently make these plant/aquarium bulbs for T5 fixtures. But they're readily available in t8/t12 sizes.

CFLs, it's quite simple, 6500k bulbs are basically on par with blue output of a Sylvania Gro-Lux bulb(the 6500k is slightly better, very slightly). A warm white bulb outputs slightly less red than a Gro-Lux bulb. Making a Gro-Lux roughly 2x as efficient for growing plants compared to a conventional bulb. Plant specialty bulbs emit a pinkish/purple light. The green is nearly negligible in these bulbs, very little watts are used to create this undesirable section of light(the WS aka wide spectrum output more green light, and have a higher CRI).

GE Plant/Aquarium bulbs are also very good(perhaps the best), and over 2x as efficient as some standard fluoros(as far as plants are concerned).

Phillips has a Plant/agra bulb line too.

Try to obtain the non-"wide spectrum" plant bulbs. The wide-spectrum bulbs have lower intensities where the plant needs it most.

Here's a document(PDF) from Phillips describing the difference between lumens and PPF/PPFD(albeit, for HID): http://www.lighting.philips.com/us_en/browseliterature/download/Horticulture_Brochure_P-5828-B.pdf

i love phillips.

i definitely will be buying stock of that company as soon as i can.