is this light burn ?

Darknes01

Darknes01

Well-Known Member
So i am experimenting with my LED lights and i think i might of given my plants a little light burn.
I am using fluence spydr 2p with dimmer.
initially it was about 20" from the top of the plants and dimmed down to 30% which was using about 213 watts each light ( i have 2 of them in a 4x8 tent )
Decided to increase the lights to 40% and this is what happened( see pics ) on a few of the clones. They have been in my RDWC for 12 days.
I did a ton of research and i came up with light burn since its only at the tops but wanted to check in with you guys and get your opinion as well.
my concern is that they are not eating too much( almost nothing ) but they are growing. so im thinking the ppm/ec not dropping fast is due to them being so small that the amount that they are eating is negligible?
anyway appreciate any and all comments.
cheers yellow1.PNGyellow2.PNG
 
Darknes01

Darknes01

Well-Known Member
rkymtnman said:
looks more like the start of a Mg deficiency to me, not light burn.
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my starting ph was 5.8 but now it went up to 6. could this be the issue? i am using lucas formula and have another setup outside in a greenhouse with basically same formula and non of them are showing any signs like this, so this is why i went with the light burn, but i could be wrong
 
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Serverchris

Well-Known Member
Yeah that's a mag deficiency, that's the only bad thing about the white light LEDs, they really make it hard to get enough mag in your plants unless your room is over 80 degrees.
 
Darknes01

Darknes01

Well-Known Member
Serverchris said:
Yeah that's a mag deficiency, that's the only bad thing about the white light LEDs, they really make it hard to get enough mag in your plants unless your room is over 80 degrees.
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Can you explain the " over 80 degrees" I intentionally keep the grow tent temps between 70 to 78. Should I increase it to over 80?
 
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Serverchris

Well-Known Member
Darknes01 said:
Can you explain the " over 80 degrees" I intentionally keep the grow tent temps between 70 to 78. Should I increase it to over 80?
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Yeah with the white light LEDs since they don't put out IR you really need to run a few degrees higher. I've seen best success at about 80 to 83. It will help with the mag uptake issues.
 
fragileassassin

fragileassassin

Well-Known Member
Serverchris said:
Yeah with the white light LEDs since they don't put out IR you really need to run a few degrees higher. I've seen best success at about 80 to 83. It will help with the mag uptake issues.
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Never heard of this before. My tent was at 80 this morning and meter shows a max of 82 and I was considering turning down the heater a bit. I'm under LED too, but just swapped them over. Guess I'll leave it, last time they started showing mag def pretty quick but it was below 75.
 
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Serverchris

Well-Known Member
Yeah I had saw a few people say this but I figured it out myself because I would always struggle with mag uptake in my veg tent which was Samsung led and about 74 degrees, every plant when I switched to my flower tent which is Samsung led and about 82 degrees would always clear up the mag issues even with the same feed so the tent temperature and a 200 more watts of light was the only variable changed.
 
Darknes01

Darknes01

Well-Known Member
got an off topic question, figured ill ask here instead of creating a new thread.
how much do your plants eat ppm wise during 3rd week of veg?
its my 1st grow so trying to figure this stuff out and have nothing to compare it with.
 
fragileassassin

fragileassassin

Well-Known Member
From what I can tell from your original pics plus 5 days, I probably still wouldnt be much higher than 300ppm of nutes.
Im overly cautious of over feeding young plants and tend to wait until they shows signs of being hungry before I up them from the baby dose.
 
Darknes01

Darknes01

Well-Known Member
fragileassassin said:
From what I can tell from your original pics plus 5 days, I probably still wouldnt be much higher than 300ppm of nutes.
Im overly cautious of over feeding young plants and tend to wait until they shows signs of being hungry before I up them from the baby dose.
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i was asking to see if u actually see a ppm drop daily and if so how much. say u have 12 day old clones about 12" tall , and today ur ppm is 300 what would u expect it to be and what would it be the next day? i hope i make sense lol
 
fragileassassin

fragileassassin

Well-Known Member
Darknes01 said:
i was asking to see if u actually see a ppm drop daily and if so how much. say u have 12 day old clones about 12" tall , and today ur ppm is 300 what would u expect it to be and what would it be the next day? i hope i make sense lol
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that young, changes are going to be pretty slow to be noticeable because they arent consuming huge quantities, but if I go down and theyve dropped 30-40+ ppm in a day Ill bump them up a little pretty much right away but otherwise wait until it drops around 50 and then bump it up 100 higher from where it started.

Slow changes makes it easy to overfeed, which is why I prefer them to tell me theyre hungry before I really start pushing much nutrient.
 
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Darknes01

Darknes01

Well-Known Member
fragileassassin said:
that young, changes are going to be pretty slow to be noticeable because they arent consuming huge quantities, but if I go down and theyve dropped 30-40+ ppm in a day Ill bump them up a little pretty much right away but otherwise wait until it drops around 50 and then bump it up 100 higher from where it started.
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im using the lucas formula (8ml micro / 16ml bloom `flora series) and im supposed to to give this dose from start till end. currently my ppm is sitting at 920( on a 500 scale) = ec 1.84 but my plants look healthy and no sign of overfeeding,or i should say how would i now if they are being over feed ?
 
madvillian420

madvillian420

Well-Known Member
Serverchris said:
Yeah I had saw a few people say this but I figured it out myself because I would always struggle with mag uptake in my veg tent which was Samsung led and about 74 degrees, every plant when I switched to my flower tent which is Samsung led and about 82 degrees would always clear up the mag issues even with the same feed so the tent temperature and a 200 more watts of light was the only variable changed.
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Its a fine line. my temps are creeping up towards 86-88 in late flower at the moment and im stressing my plant. Added a blurple to my closet for an added boost/side lighting in the last 3 weeks but i might need to remove it
 
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