I know there is no one perfect distance since setups and plants vary. But I’m curious to how do you decide how high or low to hang your LED grow lights? Do you go by plant stretch, light intensity or just iconic trial and error method?
Just wondering what works best in real growing situations.
Start with the manufacturer’s recommended height and go from there. Read about light burn symptoms and how to tell if your lights are too high. The strain you are growing makes a difference also as you stated. Some strains are a little shy and some just gobble everything you can throw at them. Bottom line, don’t stress over it.
Absolutely right about that - start with the manufacturer’s instructions.
Also keep in mind light intensity, spectrum, CO2 room temp. and humidity and nutrients all must be balanced… When you change one of those variables, the others will likely to change.
Also, look for indicators. If you see tip bleaching, either back off your r/fr spectrum for the last two hours of the day or dim the light…
In general if I’m trying to stretch my plants I’ll put the lights further away from them making them reach to get the light levels they want… as opposed to bulking up, where the added intensity rather than height adjustment …
For our lights we designed patent optics they’re really optimized with the fixtures are in an array at the same hanging height where Just like HIDs we could take advantage across beaming to normalize light intensity and collar blending beyond the cross point of two fixtures…
Unless it’s a grid light, manufacturers will be happy to do a light map for you to illustrate what the light intensity will be for your entire room.
Well worth the time IMO
I am running anywhere between 900 and 1000 watts in a 5 by 5 and so far have never burned any of my plants, guess I am lucky in that I haven’t grown any that are light sensitive. I have literally had buds grow right into the led bars at full tilt boogie and not burn when in flower.
I have some going right now that are only 4 " away and are running at full on 860 watts. There are 7 other buds that are only 1-2" farther away from that one. You can see white hairs, no burn no problem on the leaves either. That yellowing is late flower fade, not light burn.
Marty
Yep… What I am referring to is tip bleaching not burning… Burning is a general term They can be caused by pH issues, light intensity (phototropism) or heat…
Tip bleaching is caused by too much application of the 660 nanometer red during the DLI. So my suggestion of dropping the red/far red two hours before the end of your 12hours application by 2 hours will likely resolve issues with most cultivars… (we also learned adding more green also offsets the 660 over application, but Verjure and Osram The only two companies I know that integrate a green spectrum into their cannabis fixtures because it’s the least efficient…
What I am talking about is when the tips of your buds are white because they look like they have no chlorophyll… No yellowing involved there at all. It is strange specific and generally strange that can handle a high resistance to stress aren’t.
But my original point was to look at your Cardinal inputs VPD water and fertilizer CO2 and light intensity and spectrum. If you make a change to one part of the equation, you will need to off set. It somewhere else.
Example a million when people use CO2 but half of them don’t even know why… with high levels of CO2 the temperature for optimal photosynthesis actually goes up, But if you add CO2 and don’t adjust your VPD your benefits are going to be nominal… Like so many other things in nature growing these plants as a matter of balance…
No there are others that are putting green back in their fixtures. Never ceases to amaze me how people can think that they know better than mother nature. The light spectrum only changes in the spring and fall because of the longer travel through the atmosphere, not because the sun changed colors lol.
I can’t think of the name of the one I saw that added the green back in…it is on one of the podcasts by BAS on youtube.
Marty
Verjure or whatever they are called now has like 55% green… In our lights we run a bright white and a soft white diode, the equavalent of HPS and MH in the HID world. Both of those have some percentage of green inherently in the spectral range, but at low quantities. Funny that for years people thought plants ignored green… Guess now.
Its perfectly fine and welcome for growershouse.com vendors to market and support their clients here.
I apologize. I didnt know they are a vendor. How do we know who is already a vendor with us?
I use DLI readings to set my lights… I hang them as high as I can and still get the DLI I need at the canopy… when I used the manufacture distance I always burned my girls if I was to run at 100% power… I have a 1kw LED light… so my question for @californialw is how do you determine distance from canopy … what parameter are you using to determine this is the optimal distance to use…
@californialw do you have an answer for my question above…
