Lighting How much LED watts for my tent

[Arthur]

I'm running 28w per sq ft. Of COB led, might be a little shy for photos (about half what I would run HID...we'll see how it goes) for autos that's more than enough, given your not stuck flowering under 12/12. Half the photons for twice as long is still the same amount of photons...

 

[BISCUITS]

DAYLY LIGHT INTEGRAL is what you are referring to and you are absolutely correct

 

[Arthur]

DAYLY LIGHT INTEGRAL is what you are referring to and you are absolutely correct

So far, for 450w, am well pleased as to how the photos are going. @ 5 weeks everything looks to be right on track. If I was running HID I'd have 2 600 hps covering the same space... with a/c... etc... this holds temp if I zip the tent and run the exhaust. Big difference on monthly cost... @ 29cents a kwh....

 

[Mushinronsha]

You can throw as much light as you want at them. There really is no such thing as "too much" light. There is such a thing as light bleaching which can be avoided by adjusting the distance between the light source and your canopy. There is also an upward limit of light saturation, where the plant can not use anymore, however this can be raised by means of CO2 insertion into your grow enviroment, allowing you to raise temputures and allowing your plants make more use of the higher ppfd levels.

 

[Mizzo81]

Even with co2 there is a max and I think it’s 1000-1200 if I’m not mistaken and the point of best return is somewhere around 800-1000 again memory from scanning lots of info

 

[Mushinronsha]

Even with co2 there is a max and I think it’s 1000-1200 if I’m not mistaken and the point of best return is somewhere around 800-1000 again memory from scanning lots of info

No, your absoulty correct. The exact figure can range but its around there. In order to obtain amounts as large as that you would be overlapping $1000 lights at low height levels, which money like that odds are you setting up a commerical grow and have professionals helping ...Id hope lol.

 

[KonopCh]

You can throw as much light as you want at them. There really is no such thing as "too much" light. There is such a thing as light bleaching which can be avoided by adjusting the distance between the light source and your canopy. There is also an upward limit of light saturation, where the plant can not use anymore, however this can be raised by means of CO2 insertion into your grow enviroment, allowing you to raise temputures and allowing your plants make more use of the higher ppfd levels.

Yea, if you use cheap Chinese lights (120 lm/W). Then it's hard to get too much.
But if you use quallity light, like mine DIY and high efficiency (183 lm/W), then you could have too much light, even with CO2. Read about DLI.

 

[Mañ'O'Green]

I run ~33 watts per square foot for both autos and photos. I am using Orca Grow Film and I believe it adds 7 to 12 watts equivalent because it is so efficient at bouncing the photons. I do not have any way of proving that but my grows are good. Lower colas are well developed despite my lazy ways.

@KonopCh is on the right track with DLI. If you have lights that can exceed the plants uptake that is a waste of energy. But maximizing uptake means you can run a shorter day. Perhaps you get a better energy price in a shorter period The closer your day to that time frame saves money. I may be the cheapest guy here. I love to save money on a quality grow.

 

[Mushinronsha]

Yea, if you use cheap Chinese lights (120 lm/W). Then it's hard to get too much.
But if you use quallity light, like mine DIY and high efficiency (183 lm/W), then you could have too much light, even with CO2. Read about DLI.

First off, your using Lumens...which is likely the worst way possible to measure lighting when it comes to photosynthesis. And DLI is what I and Mizzo was referring too. And just for clarification, you can go over 1000-1200 PPFD your not going to hurt your plants. They just wont be able to use the light so your wasting energy/$$.

 

[Foxtrot7]

I will not grow with less than 33 true watts per square ft. I have a 2x4 tent and run 2 600 watt meizhi leds 270 true watts a piece. That's a bit much but I purchased them to go in a 5x5 along with another pair of them. Still working on 5x5

I have two Meizhi 600W over 3' x 6' of available canopy square footage. Do you think I'll do well with 5 plants in 5 gallon smart pots? Can you recommend a height for Veg & Bloom? Thanks!