My last crop showed some leaf burn in the early stages of veg. I use two HLG’s over a 2 sq meter functional grow area. !0 plants per grow. Can anyone specify height above tallest/lowest plants canopy and what intensity for the lights.
@dbrn32 @Underthestairs these guys may be able to help with that friend
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You can download the free app Photone on phone. Great app to let you know DLI and PPFD numbers. Then dim or raise light when necessary.
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What beachglass said. Just bought an hlg 350r, set it on full power, and within 2 days started getting foxtails. I spent all morning this morning reading about ppfd, and dli. Been growing for years with various lights. I had no idea. DLI is supposed to be between 40 and 60, and I was over 100. Ppfd was way to high. I dialed mine down about halfway to meet the recommended numbers. We’ll see. Here’s mine at 7 weeks from flip and the foxtails I was starting to get. Oh yeah, get that photone app. It’s good.
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Fellow grower. TY. Taking your advice for a ride.
Also depends on the light because some LEDs can be run closer than others. HLG are great lights. I have Diablo boards, they say I can get shit 15" from canopy.
Mine is about 15”, but I dialed the dimmer back to the 280w setting to get those dli, and ppfd numbers they recommend.
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All plants are different. There is no set in stone set of specs to answer your question in reality. In my 3’ x 3’ tent I have two HLG 260 Rspec lights with a UVA-30 light between them. So it’s basically a 550 Rspec with UVA. With a real Apogee PPFD meter. I was up to 870 PPFD but tent temps starting getting to high and the exhaust fan was running all the time and pulling all my humidity out in early flower. With my target humidity at 60% RH that was not going to work. I backed the lights down one notch, the plants grew 2" in one day so this morning I’m at 780 PPFD at 28" off the canopy. So I’m going to leave it there and let the plants come to the light as they set there buds. And I wouldn’t mess with that stupid phone app. I’ve tried it on a iphone 13 pro max and a Sammy Ultra 21. It would not work right on our flagship phones. Iphone read 200 PPFD high and the Sammy read 200 PPFD low. Once you get a good meter your life will be magnitudes better in the grow sphere.
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