Light heights

[Point 5]

from RQS
LED systems run cooler than HID bulbs, but they still need some cooling to prevent accidental burning of your plants. LED lights give off a great amount of light pressure, even at relatively low temperatures. This amount of light itself, not the heat, can cause light burn and leaf bleaching.

Different models of LED grow lights have different optimal distances from plants, and manufacturers usually include recommendations alongside their products. Just start at a medium distance within the recommended range and observe your plants over the coming days. Back the lights off if you notice any leaves turning pale or with burned tips. If your plants are happy, move the LED panel closer, but never to the point where the upper leaves start bleaching, yellowing, or turning brown.

High-wattage LED panels with more than 300W should be kept at least 70cm away from the canopy, then eventually moved closer during the flowering stage. As a general reference, 200–400W LED lights should be positioned 30–70cm away from plants, while 450–600W lights require a distance of 50–80cm. Higher wattage systems must be located even further away. Remember to keep a close watch over your plants whenever you start using a new light.



my understanding is its a temp thing not a light thing to have LED closer to the canopy. i have my light no more than 50cm but sometimes you just cant do that.

[TTL]

If you lower the light and turn it down I would think the outer edges and corners would start to miss out even more, no? You’re making your coverage area smaller by doing that.

[Point 5]

i use the 4r which says :
Coverage
Flowering 5 square feet (70cm x 70cm)
Vegging 9 Square feet (90cm x 90cm)

Hanging Height
Vegging 32+ Inches
Flowering 21-24 Inches

so from what Invis says i know at the height i have my light will give the adequate coverage. i did the same with the BR light. That says it doesnt cober more then 60x60 so i didnt let the plant get any bigger that that.

so the more i'm now thinking about this the height could be temp and light coverage optimization. so if you go higher you may not get an even cover?




I'm just typing thoughts now so prob not helping much

[seymore_budz]

Always follow the manufacturers recommendations when it comes to LED. IS seem to have a higher hanging height than Lumatek that recommend a distance of 30-60cm

Any LED manufacturer worth their salt normally supplies some information and normally even a coverage map.

[Treetrunk]

I run 250w QBs and 50w Cree cob lights.
I've always used 18 inch for veg and 12 inch for flower.
These heights are also recommend on Invisible sun website in FAQs.
Seems to work ok for me.


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[Smelierjoint]

Love this thread elijah mate. Point 5 is spot on there . I have been thinking the same tbh closer and less leccy. And save the lifetime of leds possibly.

But then in Stoned thought, I was thinking about the optimum range for the lights and thats surely got to be the best solution to aim for. But when do you aim for this? Veg or flower or all the way through?

Atm I am 35k from tops about 12 inch and literally on dimmest setting, plants seem fine. But am I getting the best out of things here?

Quality thread and very interested to learn more

[Donkey222]

This is something i want to look into ive been looking at apogee instruments to measure the par in my entire room once ive got all setup and saved some more pennies ill buy one and do some testing with heights, intensity and overall yield

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[Treetrunk]

I was reading about lux meters the other day.
I've not got one yet but it's next on the list.
The numbers you aim for are
Seedlings and Clones 5000 to 7000 lumen.
Veg 15000 to 50000 lumen.
Flower 45000 to 65000.
This was on RQS blog page. Sorry I couldn't share the link.

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[TTL]

Figured I’d add pictures to explain my thinking on it. As you can see, as you raise the light you get a better spread over the tent. If you lowered it and turned down the light power those corners would suffer big time. That’s my way of thinking on it. Hopefully Invisible Sun or someone who can explain it clearly will come in and tell us. Ha.

[2-Scoops]

Get them as close as you can without burning plant or causing hermies is what i was always told, basically without stressing plant out. I run 2 x 600 hps lights around 15 to 18 inches in veg and 12 to 15 inches in flowering, like fuck can i get LED that close without causing stress and bleaching, but so long as the plant is in the whole led lights array (covered in light) and its not causing any burning or too much bleaching, i figure its gonna give ya back more buddage myself, no science to it, tis just what ive seen.