Lighting Question re. DIY led distance from plants

[Olderfart]

Hello all,

I am putting together my first indoor grow. The "room" is a plywood box a bit bigger than 2'x4'x7'. I put together two light panels for this space, each with 15 screw in 15 watt leds with the diffusers removed, for a total of ~450 watts of Phillips LED lighting total for 8+square feet. First question is whether this LED power is excessive for the 2x4 space. If so, I can unscrew bulbs for some or all of the grow time.

Second question is, assuming for the moment that I unscrew the 15 2700K LEDS and leave the 15 5500K ones lit, how close should the reduced power panels be hung from the plants for germination and sprouting? Has anyone experienced light burn with this sort of LED setup, and if so, at what distance? Is it even necessary to reduce the power for sprouting?

Thanks for any help you can provide. I think that this site is remarkable in how supportive the community is in trying to help new growers no matter their background. Keep up the good work.

 

[bad dragon bzzz]

hmm with diy stuff its a case of hang it up at see what happens from there and is that 15w equivient or a true 15w ? with all the twaddle about leds we now want to know how many watts out the wall they are not the....this led is the equivient of a 250w street lamp.our led uses 100...5W chips...youd think that = 500w yeah....but the led's are onlygetting 2w each so really its a 200w led.
https://www.autoflower.org/forums/micro-growing.104/ the micro section...mr sparkle,ksjauto did a lot of work with early led lights standard light fittings
good luck n keep er lit

 

[Olderfart]

hmm with diy stuff its a case of hang it up at see what happens from there and is that 15w equivient or a true 15w ? with all the twaddle about leds we now want to know how many watts out the wall they are not the....this led is the equivient of a 250w street lamp.our led uses 100...5W chips...youd think that = 500w yeah....but the led's are onlygetting 2w each so really its a 200w led.
https://www.autoflower.org/forums/micro-growing.104/ the micro section...mr sparkle,ksjauto did a lot of work with early led lights standard light fittings
good luck n keep er lit

Thanks for the reply. The screw in leds are 15 watts actual each, 100 watts equivalent. Not sure how accurate this rating is, but it should be close.

 

[Frenjamin Banklin]

With your diffusers off I would plan on starting by using actual draw wats from the wall. Get an actual watt meter for $15. Run 20w per square foot at at least 20” in veg and see what happens. 30 watts per square in flower. You can always add power or more bulbs. You only have 8 square feet so 160 watts should produce good growth at the right height. I was going to do the same. Local dollar store had Cree par led lights for 99 cents. Still have them all in a box for a rainy day project

Less bulbs at higher wattage to equal correct numbers would be better than dimming the whole unit. I’m of the belief that running LEDs to low changes the spectrum.

 

[Olderfart]

With your diffusers off I would plan on starting by using actual draw wats from the wall. Get an actual watt meter for $15. Run 20w per square foot at at least 20” in veg and see what happens. 30 watts per square in flower. You can always add power or more bulbs. You only have 8 square feet so 160 watts should produce good growth at the right height. I was going to do the same. Local dollar store had Cree par led lights for 99 cents. Still have them all in a box for a rainy day project

Less bulbs at higher wattage to equal correct numbers would be better than dimming the whole unit. I’m of the belief that running LEDs to low changes the spectrum.

Thanks for getting back to me. I will have to look into a watt meter to see what I am dealing with.

 

[AutoNM3]

I know this thread is from October but I never heard a resolution on it. I tried this exact same thing last year all year I tried it and could not get it right because when you take the covers off those things they’re way too hot they will put actual holes in your leaves. And I mean from way up high too I was using the same 15 waters because that’s the Biggest ones you can fine yes.

 

[Hazyrook]

Not that it matters but I went to the electric supply shop where the electricians buy there supplies and was able to pick up some 65 watt led bulbs! They are badass, they even have big beefy heatsinks built in, I got them in 5000 k and I run one about 24 over males when I take them out of the tent does just fine but I didn't take the diffuser off??