I switched over to LED?

[lemonjeffery]

After 4 years of successful growing, I switched over to LED, and this happened? Leaves turned yellow on larger plants, and seedlings tips turned brown? This never happened before using my 400 watt MH, HPS, bulb set up? Large plants are 18” from LED’s, seedlings are 36” from LED’s! If I can’t fix this problem, I’ll go back to my old bulb setup!

 

[Rsawr]

I have heard that LED can cause magnesium uptake issues. Not sure how it works, I use tap water with lots of cal/mag and started with LED so I haven't seen it in person. It does look like it could be a mag issue based on the pics though? Hope someone with more experience can help

 

[budman111]

LED IME need calmag supplemented,usually in flower only due to a certain red nM or issues can get so bad that its irreversible, I have budmaster GOD and love it

 

[norcalreppin77]

I just switched to and had some of that as well, not as bad but definitely some of that. Make sure you have a solid fertilizer with all your micros... Some of that looks like light burn as well. When I first put my plants under the quantum boards 33inches and still burnt them a bit. I top dress a dry fertilizer Mr. Bs Greentrees grow and aDd some liquid micro on to of that. You want at least 1% magnesium. If not 1.5%. should clear up just need to adjust your ferts. Raise your light way up. Then once you fix the deficiency gradually lower it..

 

[IrkinBollikans]

I dont think the lights are the issue here. How many watts are you running? Do you use a pH pen? Looks like pH problems to me

 

[norcalreppin77]

I dont think the lights are the issue here. How many watts are you running? Do you use a pH pen? Looks like pH problems to me

I literally just switched 3 weeks ago. Had the same issues happen over night. Mine was light burn 33inches from the canopy with established plants. Got a lot of purple stems to. He didn't say what lights he's using. Im using the spider farmer 4000 knock offs on a 4x4 area. 390w from the wall. Still burnt mine. I was pleased to see that! Good powerful lights!

 

[IrkinBollikans]

I literally just switched 3 weeks ago. Had the same issues happen over night. Mine was light burn 33inches from the canopy with established plants. Got a lot of purple stems to. He didn't say what lights he's using. Im using the spider farmer 4000 knock offs on a 4x4 area. 390w from the wall. Still burnt mine. I was pleased to see that! Good powerful lights!

Maybe the strains I'm growing are slightly more tolerant of a high light environment. None of my plants balked when put under 500w for the first time. They just exploded. Then I added more light a week later. IME if one is using a balanced feed, then pH is the only thing stopping nutrient absorption.

 

[farmingfisherman]

How high are the lights above the plants and what are the environmental conditions like inside the tent? The more details the better if you are looking for help, people are gonna need type of soil, pot size and nutrients being used.

 

[lemonjeffery]

I’d like to thank all the members who responded, and helped me with this problem!.....I moved my LED’s all the way up, and am doubling the cal/mag, so we’ll see if this works?

 

[myke]

Plenty of info here about led causing issues with Ca and Mg,just add rollitup to your google search.

 

[lemonjeffery]

After 4 years of successful growing, I switched over to LED, and this happened? Leaves turned yellow on larger plants, and seedlings tips turned brown? This never happened before using my 400 watt MH, HPS, bulb set up? Large plants are 18” from LED’s, seedlings are 36” from LED’s! If I can’t fix this problem, I’ll go back to my old bulb setup!