It's got nothing to do with your temperatureJust got the room to 82f took a 1500w heater. But that makes me mad that I spent alot of money on these hlg 600h’s. Because now at 82f I and this extra 1500w its probably just as efficient as my old 1000w lights were.
Let me clarify my above comment: the adjustment you've made has nothing to do with your issue, if anything you've made it worse by turning the temperature up to treat a heat related problem
Ok getting mixed messages on here. What’s your thoughts on running LED rooms hotter then normal? Like 81-83f?
Leaf curling has nothing to do with temperature especially since the temp is low. The leaf curling is not a heat issue, probably a light intensity issue. The tiger striping looks like ph and can definitely be from low temps. Low temps cause lower amounts of photosynthesis which can lockout the medium and cause ph swings because nutrients aren’t being absorbed optimally. It might be a heat related problem, not having enough heat and having the light too close. Raising the temp will allow the plant to drink and absorb more optimally which could definitely help the ph situation. Leafs don’t burn at 73 degrees in veg lol
Also the reason I didn’t say raise the light immediately is because I’m the picture the top leafs in the plant are fine. If the only problem was too much light the top leaves would curl and should show the worst symptoms and show the symptoms the fastest. That curled leaf doesn’t look like it’s at the very top of the plant which could mean more than just simply raising the light. I have seen plants react like that when they are exposed to crazy humidity swings but it doesn’t seem like OP has that problem
you mentioned it only happens with that particular light (<-- clue)
I don't think HID lighting generates the same intensities of light, especially in the blue spectrum. This would explain why a lot of LED growers are seeing issues that don't appear like classic light bleaching. The picture above almost looks like a sunburn or a UV overdose. Is there any UV in the lights here is using? I'm a HID guy myself and don't know much about current LED technology.
If you think 72 degrees in a veg room is too and burning plants I have a lot of bridges to sell you
if it’s only light burn then why are his top leafs fine? No curling or discoloration. You’re doing a web md right now and saying it matches one symptom so it MUST be that. If the top leaves do it first then it’s definitely light burn, if not then it could be something else. Burning under led looks different than hps as well, that’s why you can’t just look at one light burn picture and say that’s what it is lol. 36 inches in veg is perfect for the hlg light and shouldn’t burn that much at all. You don’t know if raising the temp could help, saying it flat out won’t is a bit ignorant. Many deficiencies and problems share similar signs, stop trying to web md the OP and try to actually figure out the problem
Agree, and he says several times that it only happens under those particular lights, & that's the gist of my point, again.
No Uv in hlg lights and spectrum of light doesn’t much matter, intensity does. 1000
light burn is less common under leds than light bleaching. The burn comes from high intensities and high temps which go hand in hand with hps since it pushes so much more heat toward the canopy. With led you don’t have that heat problem so you usually just see the signs of bleaching and minor burning since it’s not also burning from the excess heat being thrown into the canopy as with hps at high intensities
The lower leaves are affected and not the top... by the look and age of the bottom leaves, this is something that could have happened a month or so ago and just showing up. I had similar looking leaves after fighting off spider mites... the damage didn't really show up until flowering started. When I used a 10Kfinishing MH bulb, the problem on the older leaves became very apparent very quickly with only the older leaves being affected... almost exactly like the picture in the original post. Were more lights added or changed somehow? I agree that all signs point to the lights, but a small piece of the puzzle still seems to be missing for a perfectly fine growing plant to suddenly go south with only older leaves being affected. Flowering pulls nutes from older vegitation, but it doesn't typically look like this unless there was prior leaf damage under the canopy.
Thank you @Beachwalker ... it's very good to be able to be here. You don't think much about dying until you either die and come back, or nearly died. I decided to come back, but it has been more than a walk in the park! In any event, I'm here to write another post and hopefully help another grower, although it can sometimes be a thankless way of donating your time and experience. Keep up the good posts!
