Mystery problem, nutrient overdose? deficiency? insects? [solved?} for now

This could be a slight to moderate nitrogen deficiency!

Young leaves look OK, older leaves having troubles.

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@oranje how did you resolve the issues you had? I am using LEDs and have accidentally bleached plants before. The krinkly leaf plant is kind of a wierdo mutant. Itā€™s pretty far from the lights since it is so short.

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my blurple LED (120 x ā€˜10wā€™ equivalent diodes) needed to be 4-6 feet above the canopy or it would stunt and then bleach. i couldnā€™t find the photos iā€™ll look again

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Yikes! Mine lights have worked with no issues at around 10" above the canopy. Right now they are higher though because Iā€™m trying to cover a larger area than usual to finish up a straggler that I was expecting to be done a month or so ago.

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i have two leds in veg a 300w and a 450w they are about 15 to 18 inches above the plants. Once you find that sweet spot your good. I think the new led tech is better and most of the newer lights ie spydrx and such that are white light ( to us) are designed to be hung closer to the plants than the older style led lights.
OG

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I thought about the respiration damage since the leaf edges kind of look like they have some salt build up on them. You might be right. My temps are pretty low though. 66-77 degrees F and humidity between 48-62 percent. Maybe just too high EC or salt build up. They usually get watered to runoff and I havenā€™t had this problem before, but a bunch of stuff has been messed up this run.

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Iā€™d say nitrogen deficiency or septoria. If youā€™re not seeing this at the top of your plant then itā€™s probably not an N deficiency unless itā€™s in the real early stages. Some of the necrosis almost resembles the effects of wind/light burn. Phosphorous deficiency is usually accompanied by dark red stems.

Good luck!

beam angle is important with LEDs too, it makes a huge difference. A lot of sketchy lights have narrow beam angle and a small fixture that blasts the plants directly below.

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The bad news is that I effectively changed everything, but very briefly summarizing in case youā€™re still curious:

Over the summer I was having nothing but problems in veg, under a Mars Hydro LED (think itā€™s 130 watt?) supplemented with 96w of T5s. I kept the LED about 18"+ from the canopy, which sounds entirely reasonable for an LED, and this worked just fine for me in the previous months.

Anyway, things were growing extremely slowly, new growth was bleached a sickly green-yellow, and old growth had leaf lightening between veins paired with crispy-burnt leaf tips/edges. The crispy death would slowly devour the given leaf from the tip over the course of 7-10 days. Figuring it was water/food related, I got an RO filter to rule out water, switched up nutrients, flushed, switched soilsā€¦ could not change outcome, could not find an answer.

When I finished up my summer flowering, I moved all my vegging plants into the flower tent ā€“ HPS and CMH for lights, but otherwise similar environment. Plants started to improve rapidly. But. This was also around September, and lower AC use resulted in a mild (10-15%) increase in RH.

A month later, I swapped out the veg tent lights for a SolStrip setup, moved in plants, and things are going swimmingly. But, again, variables ā€“ completely different season by that point, much higher RH and cooler tent overall with new lights. I cannot definitively blame the light due to other environmental variables.

No moral to the story, unfortunately, but if something in there helps, glad to be of assistance :grin: Again, hope you can nail down your issue soon ā€“ still look like pretty solid plants, for what itā€™s worth.

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Look harder. My plants looked very much like yours earlier this year. Turned out to be thrips. They are hard as hell to see. If you have ever walked through a cloud of super tiny flying insects, those were thrips. They are a real bitch. The adults leaf mine causing one kind of damage. Thrip larvae are microscopic and travel all throughout the pot damaging roots at many different levels, causing what appears to be nutritional damage to the leaves as well. See the attached pic of thrips and gnats on a sticky.

You are going to need at least a 25X to see the larvae. There are several ways to find the little bastards. One way is to put potato slices on the top of your dirt (or other substrate) for several days. When you then look at the underside of the slices, you should be able to see some. The worse the infestation, the more youā€™ll see.

25X makes them visible, 60X will let you see what they actually look like. The thrip larvae look like white caterpillar with no fur. They have what looks like 2 antennae at one end these antennae have dark ends. It actually appears as if they dark ends are actually eyes, but I canā€™t see enough detail with a hand held microscope to verify if that is indeed what they are. Very difficult to finds images online. Do a search on thrips and you will find about 100 articles about gnats for each one about thrips.

The other way I know of to check for thrip larvae is to water suspect plant until you have runoff. Then take the drainage dish and look in there. I bought a Celestron handheld digital microscope (about $90 on Amazon) to do just that. The ā€œmicroscopeā€ is really just a 20X macroscopic camera with software zoom. So, you donā€™t get any kind of detail with it (software zoom loses detail badly), but, you can identify them and see their movement. The little fuckers swim like tadpoles and crawl like caterpillars. You are also likely to find adult thrips in the drain dish. I think they are newly emerged when they are there, not strong enough to fly out. Where adult gnats emerge topside. Thrips seem to emerge from the drain holes. Some may exit topside, they are, after all, Very difficult to see naked eye. They donā€™t fly the same as gnats and the seeming randomness of their flight looks much like dandruff flakes or lint floating on fan induced air currents.

So, take all the advice about nutes, but look really hard for garden enemy #1 (in my grow anyway). I had them last year, before I knew they were not gnats.The plants that did survive produced very little. I was lucky to have big enough harvests to avoid needing to purchase weed. I had to cutback radically.

I was so certain I was doing something wrong that I bought a lot of different nutes that now sit on a shelf getting dusty.

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Well things are looking better. I leached the media for a couple of days by just adding pH adjusted water to the reservoir and watering 3 times a day with a lot of runoff. Added Epsom salt to the mix and have been feeding lightly around EC .8-1.2 for the last couple of days. Plants are looking better and I havenā€™t seen any new damage.

I think it was a build up of too much salt in the media. Even though I was watering until runoff, I donā€™t think it was enough with the strength of my solution. I think because of the high concentration of salt the plants were transpiring a lot. Possibly transferring salts to the surface of the leaves and burning them (not sure this is possible though)

Extra Mg in the new mix is probably helping as well.

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i think it may be possible, high temps would also make them transpire/drink more i think. i am glad that worked itself out. iā€™m going to save that picture of damage for future reference, had never seen that before

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@HappyGoLucky21 i know itā€™s old but interesting.

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Thank you! I got my readers on, very good find!

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This girls on her last leg.

How many weeks? Not all seeds do like we want. One thing that I do wrong isnā€™t keeping a mother. I do like clones. Seeds are just sweet