question ? Is a PAR of 538 at 24 inch height a good spectrum indicator. Thank you in advance for your input.
@dbrn32 is our lighting expert. He will be along when he gets a second 
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Thank you !..
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Where did you get the 538 number from? That’s an indicator of intensity not really light spectrum but no biggie.
I’m asking because if you take s light that’s something like 13”x18” and stick it in a 3x3’ tent, and it has s ppfd measurement of 538 umols directly under it, the further you measure away from center that number is going to drop significantly. Lowering your light will give more intensity but at a point will diminish your coverage. Most of the inexpensive lights for instance don’t give you a total ppf output for their lights because it’s not competitive with the lights they advertise it will replace. So instead they give you that single spot measurement from directly beneath that looks impressive to unknowing buyer. But in reality doesn’t really provide the results they advertise it will. When you get into lights from the industry leaders they will give the total light output of the fixture and a recommended flowering footprint targeting a ppfd average usually between 600-1000 umols per second per square meter.
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here are some specs from the site. I really appreciate your rebuttal but so much of it is over my head, something else to research. Thank you very much for your response. Happy New Year !
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How big is your grow space? Look at the fall off in numbers out to a 2x2 area, that’s exactly what I was talking about above. Minimum recommend flowering intensity is a ppfd average of 600 umols/s/m2. You don’t even have a hot spot reading that high at that height.
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20 square feet, but thank you for the insight I was able to cancel the order for 2 of those lights after receiving your insight. What are your recommendations ? Thank you !
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Is it like a 4x5 or long and narrow?
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4 wide 5 long and 6 high.
I only grow 1 or 2 plants at a time…
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Do you fill that space with the one or two plants? I’d like to get the space you use lit properly, then it doesn’t matter if you grow one plant or 10 plants. I also don’t want to recommend something that will cover 20 square feet if you don’t need it.
Also, is this a seed to harvest growing space? And do you specifically want led or other types of lighting a possibility?
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I have a 2x2 converted bathroom vanity for starts and seedlings, I have a 3x5x6 room for veg and the 4x5x6 for flower. I currently use 3 full spectrum 45 watt leds and a 4 ft fluorescent fixture with 3 3000k bulbs for flowering.fluorescents are vertical to the plants. I guess my actual growing space with 2 plants is more of a 2x2 area. I have 1 led in the vanity with 3 seedlings and 3 in germination and my veg room is empty right now. 
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A 2’x2’ area is piece of cake. I would grab qb 135 kit for that. You can save a couple bucks assembling yourself or have growerslights assemble and test for you at small fee. For a light like that to be most effective, I would also wrap the space you’re actually using with reflective material of some sort.
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all 3 of my grow spaces are completely wrapped with 2 mil mylar…
If you’re only using 4 square feet in a 20 square foot room you narrow the area you’re using down to 4 square feet with something reflective is what I’m saying. Keep all of the light within that area instead of spilling out to where you don’t have any plants.
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Oh, I got it now !!! Thank you…
…I really appreciate that input, Im constantly rearranging the lights and moving the plants around now this makes total sense. I can use the vanity seedling room as an example, small space wel;l aerated, 1 light 3 seedlings 3 seeds in dirt in a 2x2 highly reflective space and apply that to the larger grow spaces based on the amount of foliage in this case 2 flowering. WOW thank you for opening my mind to that, I will keep you updated !!
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No problem, glad I could help.
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OK, per your suggestion I reduce the space to a 2x4 area with a 4 ft fluorescent with 3 3000k bulbs vertically and a 4 ft fixture with full spectrum leds at 45 watt horizontally and a 4 ft piece of plywood with mylar on the reducing side. Here are a few pics for your review. I also included 2 pics of my start booth for seedlings and vege. Thank you for your input.
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That looks good, the reflection will help keep light levels up.
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Thank you, I am at day 21 of flowering and want a harvest your insight and suggestions are greatly appreciated. I will start looking into better lighting resources as soon as the $$ allows me to.
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