Light Selection

[Sentinel]

Would 2 40w fluorescent "aquarium and plant growth" lights be good for 8 plants?

[stickygreenlightsabr]

Maybe for the first couple of weeks. You'll need a lot more lights after they start their veg stage.

[Sentinel]

I seem to only be able to find those long 40W fluorescent tubes. I could get lots but do i need any different kind of light?

[genuinestoner]

40 watts no good, i started with that and TERRIBLE results. you need (depending on space and money) at least 150 MH then 4 veg 250 HPS. works for me!
good luck!

[HARDDON]

Would 2 40w fluorescent "aquarium and plant growth" lights be good for 8 plants?

No. You would be better off with 2 40W COOL lights.

But that wouldnt be enuff light for 4 plants either....maybe for a couple of decent ones during veg stage only though.

[Lady Vapor]

Get better lighting or it will take you foreeeeeever to see the end of the grow, if it gets that far.... And you won't get much more than grief!

[Sentinel]

shit i cant seem to find anything but 40w fluorescent lights. God-Damn

[HARDDON]

so use 10 of them :)

[meloncoly]

"shit i cant seem to find anything but 40w fluorescent lights. God-Damn"

try the Internet

[Sentinel]

Alright.. im thinking i am going to get 4 40 watt cool lights for the first week or 2, then get 6 warm lights and use them all. ive heard that cool lights supplementing warm lights are good...

[mafia819]

it does a bit but, i strongly suggest you buy a 400w hps ballast and bulb for 10 plants... flowering with floros always give what the floros can push... very low yield even if they are warm bulb or whatever...!
There's some good place to buy hps light on the web... try this one: www.hydrowarehouse.com


Hope this help ya ;)

Happy Growing! :D

[Str8jeepin4pack]

I would really suggest that you use the flous only for cuttings/seedlings and with 10 plants depending on how well you have them spaced out will depend on the light size you need. You can cram them all into a close space and do the sea of green thing, but a 400w HPS can cover up to a 3X3 area. You want at least 45 watts per sq. ft. A 400 will give you 44 in a 3X3 area which is ok. Here are the demisions that lights can cover: 400W 3x3 max 5x5 600W 3x3 max 6x6 1000W 4x4 max 7x7. You need to check online for a light or if you tell me you area i can tell you or a hydro store near that will have everything you need.



green leaves

[HARDDON]

Green leaves....

Why, out of curiosity, do you formula the WATTS per sq and not the lumens per square?

If I invented a special light that cast 8,000 lumens per sq......what would it matter what the wattage is?

Lumens are rated at 12" so why the wattage scale and not the lumen scale....?

Just curious :) thanks.

[Marc Benson]

Since I now know you love to read HD (and you thought HD meant Harddon :D) here's some for you.

"Lumens are a measure of light output in wavelengths to which the human eye is sensitive. It is not a meaningful or useful measure for plant lighting. Interestingly, the SI lumen is defined in terms of the candela, which is in turn defined in terms of watts. The wavelength defining the lumen is approximately 550 nm, a wavelength that is not very efficient for growing plants.

The watt is the SI unit for power and also for radiance. The first is the measure of electicity used by a lamp (e.g., 400w). The second is the light emitted from the lamp at all wavelengths.

It can be very difficult to obtain ratings for lamp output in terms of radiant flux (watts). Different lamps will have different radiant efficiency (how many radiant watts are produced per input watt). The exact spectrum produced also determines how useful that light will be for plant growth.

That still doesn't make lumens useful. 50-60 watts (minimum) of HID lighting (double that for flouro) is a rule of thumb that is at least as useful as any lumen recommendation, and has the further advantage of not further promoting misunderstanding of a very misunderstood subject, or further propogating the misinformation that lumens are at all useful for our purposes."

and

"The lumen is not a useful unit of measure in this regard. In fact, for any two lamps of the same technology and wattage, the one with higher lumens very likely produces less useful light for plant growth than one with lower lumens. Why? Because lumens are a measure of how close the light emitted comes to 555nm. But light between 500 and 600nm is not very useful to the plant. Low Pressure Sodium is the perfect case in point: it has the highest luminous efficiency (lm/w) currently available, but is useless for plant growth (otherwise everyone would have LPS lights in their grow room). GE Plant & Aquarium flourescent bulbs are another case in point: they have very low lumen ratings, but provide much more energy for plant growth than other kinds of flourescents with higher lumen ratings.

Lumens are used as a proxy for "intensity" by people who don't understand what a lumen really measures, or the difference between photometry and radiometry."

and

"Because the overwhelming majority of lamps are designed for human vision applications, lumen ratings are required for all lamps. However, the SI defintion of lumen is 1 lumen = 1 candela * steradian. One candela is the power in a given direction, of a source that emits monochromatic radiation of frequency 540 x 1012 hertz (approximately 555 nm wavelength) and that has a radiant intensity in that direction of 1/683 watt per steradian. So we see that lamp output ratings really do start with watts and then derive lumens (according the the CIE photopic vision curve)."

[HARDDON]

Was sounding really good till I read this:


GE Plant & Aquarium flourescent bulbs are another case in point: they have very low lumen ratings, but provide much more energy for plant growth than other kinds of flourescents with higher lumen ratings.

Whomever this is saying this is not a stoner.

I will never be convinced that a GE Plant and Aquarium is superior to good CFL's for an outdoor plant grown INDOORS.

No way :)

TO use his own logic in sense, I would reply in his very own contradictory words....


(otherwise everyone would have LPS lights in their grow room).


I would just replace his LPS and substitue GE plant and aquarium bulbs.

THis is against everything I have ever learned, experienced. Sounds like a new science geek.....growing more than tomatoes. Some day I shall show my real ferns :)

Watts are not more important than lumens.

Other wise we would all be growing 150 soft white incandescents....

Right under the kitchen sink light.

But thanks for the time and courtesy Sir MB :)

[Str8jeepin4pack]

Easier for the average person to understand and lumens are determined my the brand of bulb not watt. Most 400 w bulbs for example have 53,000 to 58,000 lumens .. . sounds like huge difference but really not

[Marc Benson]

HD I got into with him too as we've all had lumens lumens lumens yammed down our throats. If you start telling people they need to go by watts now it'd be a cluster. And of course watts for HID's would be different for watts for CFL's but I think he suggests that. But in the support of watts, IF we had all been 'brought up' thinking we need 400 watts of hps to successfully grow tomatoes in a certain amount of space, if someone then said you have to go by how many lumens instead of watts everyone would be calling him a witch doctor. It's all in what we're used to.

Where I think he was coming from with the aquarium lights is that possibly they have a better light spectrum than some fluorescents. Less lumens (lumens lumens lumens) but better usable light. Just my take on it. Don't know if he's correct or not but he's a very successful grower of some fine looking tomatoes!!

[BobBong]

Approx. 900 watts of CFL. probably less due to age of the bulbs. but either way.. that much is what i've been using for 2-4 plants.

so no, 80watts won't cut it.

Depending on where you are and what kind of money you're willing to spend. you can lights like these..even better ones online.

these were 14$ canadian. not bad all things considered.
lights! (http://www.1000bulbs.com/product.php?product=6730)

[Str8jeepin4pack]

i agree totally i was just saying an easier way to figure out what amout of space you can cover is go my your watts . . . also if you go by lumens you can find yourself getting overkill on whats . . . more the 65 per sqft is a waste. but i agree lumens is the best to judge but its easier to start out by determining your watts you need


green leaves

[HARDDON]

Mr. Bong....

That light link....

55 Watts, Equal to 240 Watts ****It is 55W...not 240...You can't count these in your totals.
Color or Hue = Warm White, 2700 Kelvin ****THese are flower bulbs.

Are you going to flower them with these 2700's? I would like to see how they work before I spend $195.00 on the 200W 2700K I am wanting to buy bad......

They would be so awesum on starting clones to flower.

And thats the direction I am heading.....clone city.....