Lumens, Lux, and Adding It all Up

Discussion in 'Indoor Growing' started by ceestyle, Jun 19, 2008.


    Figong Well-Known Member

    That's a good question, and some have their own preferences that are dialed into a grow.. I'd generally go 7000-7500 lumens per sq ft for veg, and 10000~ per sq ft for flower... I'm picky about my numbers and everyone will have a different answer as to what's optimal - especially when you have conditions that have your light higher up than it could otherwise be due to ventilation issues or other.

    bongwater830 Member

    Thanks Figong! Can this be accomplished with CFLs? :peace: bongwater

    Figong Well-Known Member

    I've never grown with CFL so I wouldn't rule it out entirely but it could be difficult depending on how many bulbs you want to use, proper wiring to avoid fires, and other things that must be taken into account.

    rcpilot04401 Well-Known Member

    I tried reading this thread to try and figure out my light seems like it was a waste of 2 lights, one running at 400 watts and the other at 600, are giving off 42,700 lux at about 10 inches...had I know that this was going to give me a migraine and blur my vision I wouldn't of even bothered...hopefully that's a good number...any suggestions?

    Highlowazupkush Member

    Hey does anyone know of such lights as what they are talking about? 3k lumens per tube. Brand names might help.

    weediologist Member

    NO am the Weedologist :bigjoint:

    shadyslater Well-Known Member

    Bro you can get like 300w actual draw cfl's. Ive been running a 125w actual for 18 months now been givin me an oz per lady per cycle

    jackm420 Active Member

    too bad lumens aren't cumulative

    Abiqua Well-Known Member

    or useful......
    chazbolin likes this.

    Dracolyes Member

    lol pointless discussion on cfl

    zhzzhg New Member

    kay, so saying the lux doubles, but what does your meter say in lumens rather then lux? [​IMG] [​IMG]

    acutejunglerot Well-Known Member

    quick question. i am buying a 6 ft light rail for my 600 watt xxl hood if i let the light trolley the full 6 ft what will be my total lum covarage area. i am trying to keep it as evenly spread as possible. :dunce:
    i am trying to cover an area of 8' x 15' x 8'. would two side by side be better. what would be my length limits as to how far light will be adiquitly thrown. ty happy growing!!!

    arhdhath New Member

    okay, so saying the lux doubles, but what does your meter say in lumens rather then lux? [​IMG]

    hydrolyzed Active Member

    So Cee.....why the hell aren't you testing Cannabis for its PUR requirements, and then designing us a super efficient LED light with perfect spectral patterns and wavelengths, only that of which our plants can use? hehe hint hint.

    What do you think, compared to a 1000w "average" grow HPS bulb, the efficiency would be if we took ONLY the PUR energy from it? I know you said it will be close to PAR watts, so, probably 50% savings? I'd like that, half the electricity, same yield, or same electricity, double yield! ( I know that's a lose statement, just saying for fun)

    ..BULLIT.. Active Member

    Nice thread .

    if i speed up the speed of light will my plants grow quicker than if i don't , side by side
    two lights
    two plants
    turned on the same time but one iv magically speeded up the light ......which will grow faster ?...... Just saying .

    ..BULLIT.. Active Member

    ^^that was a joke not a troll thingy post . Seriously nice thread

    Sagethisplanet Active Member

    Get another hood!n. The mover won't be consistent imo and might as well get another 600aa they are the most efficient per w. And lumens don't matter, PAR does.n. So don't be fooled, get the right color spectrum going.

    meristem Well-Known Member

    I'm trying to count photons but they're so fast I keep losing count.
    Skunk Baxter

    Skunk Baxter Well-Known Member

    I've read the entire thread, but if the answer to my question is in there then I was probably too dense to recognize it. Nevertheless, this seems to be the appropriate thread to ask the question.

    Using a luxmeter, is there a way to determine whether an HPS bulb is failing? For example, if a I have a 1000W Eye Hortilux Super HPS bulb, is there a standard unit of measurement I could read with my luxmeter to tell whether the bulb is working properly?

    Reason I ask is I have just such a bulb, and a few days ago it suddenly seemed to give off significantly less heat than it had been. I can't really tell with my naked eye whether the light has dimmed - it's still very bright, but doesn't seem as bright as a 1000W should be. I know that could be my mind playing tricks on me, so I want to measure the bulb's intensity, but I'm afraid I don't know how.

    Using a luxmeter, I get a reading of consistently between 65500 and 67000 lux measured 1 foot directly below the bulb. But I have no idea how to use this information to tell me anything about whether my bulb is working properly, because I don't know what the reading was a foot below the bulb before I got suspicious of it.

    Is there a way to do that? Some sort of charts or conversion tables somewhere that will allow me to take that value and compare it to the known values of a "healthy" 1000W Eye Hortilux bulb? Is there a standard distance at which I should be taking the reading? Do I need a PAR meter, or some different unit of measurement than lux? I know this probably sounds like a stupid question, but this has never come up for me before. But it would be useful information in the future, too, so that I can more objectively track the status of HPS bulbs as they age, and perhaps help me better anticipate when they need to be replaced. I tried looking up the information on Hortilux's website, and all they say is that none of that matters. Trouble is, it kind of matters to me.

    Thank you for any help you can provide.
    Father Ramirez

    Father Ramirez Well-Known Member

    Of what I've read consensus says 35-40k lux at the canopy is ideal for our purposes. Over that the light is wasted at best, and can stunt growth. Some equatorial sativas can use more, but still not over 70k. I can't speak to your original question about diminishing brightness, but your light is plenty bright as is. Adjust height to find the sweet spot. Happy growing!
    Skunk Baxter likes this.

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