After I started using LEDs very close to the foliage I got this mark, do you think it could be nutrient burn?
it looks like its in; 1. to small of a cup. 2. not in good soil. 3. not in enough soil. 4. whats the PH. 5. if you fed it, dont. 6. FLUSH
It's a huge cup, the plant is 4" tall. I agree soil is not great. pH is 6.9 I did, it was an experiment. I used 6 hand dropped nitrogen GRAINS and a teaspoon of espoma biotone. I have been, they just keep getting overwatered I may have to start over.
I got better soil and transplanted, gently removed soil from root mass. I bought Miracle Gow soil (no additives) it was the peat moss variety so it is very fluffy and small grained. I added a few hand fulls of schultz vermiculite and tossed it like a salad, we will see how this does between watering:
Nope it's actually a tiny UFO in a small box, the plants are also extremely short and bushy so it throws off the size comparison. Thing works really well though I must say, the light spectrum really is engineered specifically for plants and it shows.
hell yeah son, im rockin a UFO as well. 5 of my pants are around 15 inches away from it and all 5 are growing nicely. props for being on the cutting edge with me bud lol
looks like light burn, if you notice in the first pic you posted at the end of the leaves there is a point downward at the very tips, this indicates that they are getting burned/too hot. check your temps and adjust the light to see where it's best to leave it at.
Don't they curl up when too hot/dehydrated and down when too wet/cold? If 82F is affecting them now I will never make it through the summer. I was able to keep my CFLs closer than this LED, dosent make any sense.
you are thinking of the entire leaf curling from over/underwatering. the tips curling like that is from heat stress usually. edit: you ideally want your plants to stay at 75 degrees, they can only handle higher temps if they have a lot of co2 coming in. my tips started doing that when the plants got closer to the lights and the temps were 80+ degrees
Darn, looks like Co2 injection will be part of my cooling design lol because I can only get it so cool, I bumped my 12v fans from 6v to 9v and it dropped 6-8 degrees. Looks like I will be running the lights at night instead, I have a 120mm intake and exhaust maybe a circulatory fan will help temperatures.
From my personal experience, LEDs can burn your plants (not by way of heat) if too close. I am not sure what causes it. CFLs I can keep about 2" way from the plant and prevent heat damage. But, my 300w LEDs need to be about 12-16" away. It depends on the strain though. Some are more sensitive than others. And you may want to be gradual with the light. Seedlings do not need very much for the first week or two, then a bit more, then everything.