Anyone know what causes this?

Not sure if it is a big problem like pests or nutrient problem, I’ve had fungus gnats for a few weeks but took care of most of them with mosquito bit tea, and the sticky yellow traps, my only thought is leaf miners maybe? Or something to do with the nutrients, happens to a couple leaves over a week or so

If it's only a couple random leaves it's likely nothing to worry about. Nute problems will show up on all leaves in the same class all around the plant. Like low N will start causing all the oldest fan leaves to begin fading to yellow and bad pH will cause micronute lockouts making the grow tips look weird.

OldMedUser said:

If it's only a couple random leaves it's likely nothing to worry about. Nute problems will show up on all leaves in the same class all around the plant. Like low N will start causing all the oldest fan leaves to begin fading to yellow and bad pH will cause micronute lockouts making the grow tips look weird.

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Thank you so much for the feedback! Yeah, it’s just a few leaves. I did have 1 leaf that had 3 straight brown lines going from side to side, like a leaf miner strip I have not seen anything like it since I I plucked the fan leaf.

So I am now running into the problem of seeing more and more of these leaves? Any suggestions? PH runoff is 6.2, I’ve been giving them 3 wk cronk nutes, and just flushed them due to salt buildup, I’m guessing it’s more so a deficiency problem with the leaves the way they are

RiverRunzRed said:

So I am now running into the problem of seeing more and more of these leaves? Any suggestions? PH runoff is 6.2, I’ve been giving them 3 wk cronk nutes, and just flushed them due to salt buildup, I’m guessing it’s more so a deficiency problem with the leaves the way they are

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Those leaves are too dark for it to be a deficiency problem in most cases. More likely an excess of something interfering with other things.

Almost looks like a boron deficiency which is rare but I had one like that a few years ago and after a dose of boric acid from the drug store it stopped. It's about the only thing that starts off with necrotic spots between the veins.

What are you growing them in? And what are you using for nutes? And how are you collecting a sample of the runoff for testing?

Take a look at this chart. I've found it very useful to ferret out problems with my plants over the years but you really have to play detective sometimes to figure things out. As you've already flushed giving a well balanced, half-strength feed often fixes things.

I use Happy Frog potting soil, in 5 gallon fabric pots on risers in catch pans for PH run off, I am using Cronk Nutrients, cal mag, micronutrients, grow and bloom, I have a PH meter to read run off into catch pan and PH up and down to set proper PH on feed. Would it hurt if I gave it some boric acid?