Light stress? Magnesium deficient?

Anyone have any idea on what I got going on here? Day 24 of flower. Super Lemon Haze grown under the Migro Aray 4x4. This is my 4th run with my soil, reamended with Build A Soil craft blend, and worm castings. I let it sit for at least 2 weeks before planting in it. I’ve never had this issue. I have a Jelly Donutz from Humboldt right next to it, in the same soil, and it’s thriving.




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Hi there, rule out Mg deficiency. It drains from old leaves to supply newer.
Just a suggestion lack of zinc or sulphur can yellow new and upper foliage. See accompanying symptoms, leaf charts. If it’s a deficiency

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What percentage is your lights cranking?
It does appear as a magnesium deficiency, but lights that are running hard will do this too.
I increased my Epsom salt dose to make up for the deficiency when running the lights hard.

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My light is at 80%, it’s 24 inches away. It got as low as 20-21 inches cause they grew into it before I checked the height again. I thought about adding epsom salt, but I wasn’t sure it was a magnesium deficiency. I top dressed more craft blend, and worm castings 6 days ago. I got mycelium growing, so hopefully it’s being broken down fairly quickly. You think I should add epsom salt, or it would be overkill?

I think if you added some it would be beneficial and prevent it from getting worse.
I would recommend dialing the light fixture back a bit. But 80% seems reasonable. Could have happened when they grew into the light a bit.
Those leaves will stay that way, watch for new normal growth.

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I thought about leaving it at 60% (300w). I turned it up to 80% for flower. A lot of second guessing on my part. Thanks for the help, i’ll definitely add some epsom salt next time I water.

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I agree looks like start of mag deficiency. Epsom as suggested. Or cal mag which is good also. Fast growth in organic/ living soil can take a bit to keep up. Newer growth can take longer to get darker green. Other than that look just fine. In flower and just 300w so I dont see light as the culprit. Just my thoughts.

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Thank you

My light was on 60% this whole time, which is 300 watts. Not 80%. I have two plants in a 4x4. You think 300 watts is enough, or you think I should turn my light up to 80%? I don’t go by how much par my plant is getting, I like to keep my light no less than 24 inches away.

If you have the head room in your tent, bump it to 100% and raise it up if you have to, youll likely get a better coverage area for a 4x4. Photone app is pretty handy, and is accurate if my lighting companies ppfd map is true lol

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Happy Versery @NorseRow :beers:

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Thank ya!

I have the photone app with the accessory. I swear if my light gets lower than 24 inches my plants get stressed regardless of the par reading. My last grow I tried to go by the par reading and I put my light at 12 inches with a par reading around 600 for flower and I fried my plants. Lights are definitely something I haven’t grasped yet.

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Some plants are more sensitive than others. This one may not like that much light. I remember you said it grew into the light, and then raised it.
Light burn can happen pretty quickly, or over time, conditions and fixture distance are the variable.

Last question, how much epsom salt per gallon do you use when you use it?

I use 1.7g of Epsom per gallon when mixing nutrients.

Yikes! Sorry to hear that. Yea i feel ya, some times is just the plant, usually i dont have to move my lights and my intensity its pretty predictable, but ill have ones that stretch too much and others thatll start burning🤷‍♂️ just gotta be adaptable i suppose

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Thank you.

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I watered yesterday with 1/4 tsp of epsom salt and gypsum. Also did a slurry test and the ph read 6.5 so it isn’t a ph issue. Hopefully I corrected the problem

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I hope so too!

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