Led light distance

What is best practices for led light distance?

Reviewing articles Best Grow Lights For Indoor Marijuana Growing

I see distances of every other light MH/HPS etc… But none for led.

Using VIPARSPECTRA 200w

It should have come with a manual. Mine is a Viparspecta 900 and it says start at 36"-40" for seedlings lowering to 24" for veg, then 15"-18" for flower. Or something like that.

Here’s a chart for LED lights, it’s for equivalent watt, so if your LED light is 300W follow the chart for it, it’s not made for actual or real draw, that clarify, here it is :

120 W to 180W ~1.5 feet
180W to 300W ~2.0 feet
300W to 600W ~2.5 feet
600W to 1200W ~3.0 feet
1200W to 2000W ~3.5 feet

Hoping that’s helping you @BrockSamson

~Al :v: :innocent:

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So as far as I can tell my light is working well, I have the same instructions as @Matthew420 and I started at those recommendations however I only saw any real growth (seedling stage) much closer to +/- 12 inches. Which instruction wise felt too close.

I understand the need to “read” your plants and adjust based on their reactions to the light.

The link in my post refers to distances for all the common lights but doesn’t list LED suggested heights and this was the basis for my question.

Great post @Niala, thanks for that!

:v::evergreen_tree::evergreen_tree:

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You’re welcome @ktreez420

~Al

@Niala. Hey I just seen your chart about led heights. I really need help. I have a wwa and a California dream about 3 weeks old under a roleroleadro 2and generation about one foot above them and they are loving it. But, I have a cali dream about 3 weeks into flower and a ww about 7 weeks into flower. I have a roleadro 300 and a 400w cob in tent. Cob above the ww and the 300 above the cd. I can’t seem to get the height right. The buds on the ww top 3in is good and tight. Below that they are airy and small. Any info would help, especially if someone has used the same light. Thanks in advance

I’m afraid this is a common occurrence with artificial lights. The suns rays are almost perfectly parallel so all parts of the plant get light at the same intensity. Artificial lights usually have inverse square law ray spreading. So the top of the plant is 14 inches from the light and the bottom is 28 inches. So if the top is getting 40000 lux then the bottom is getting only 10000 lux! Buds don’t do well with 10000 lux. You might want to add side lighting toward the bottom.

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I have a bestva 4000w grow light what is the right height for seedling?

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Welcome to the forum.

Light intensity is measured in PPFD (photosynthetic photon flux density.) Get the free Photone phone app and use it to measure PPFD. Here are PPFD minimum guidelines when measured at the tips of the plant:

Seedlings: 300 PPFD
Veg: 600 PPFD
Flowering: 800 PPFD

I’ve grown extensively with LEDs. You should be keeping the canopy 8-12 inches from the light fixture.