Several leaves have developed spots like this over the last 72 hours. The plant is 26 days old and otherwise seems OK. Any thoughts on what it is? What do do, if anything.
When you water avoid to wet the leaves, the water cause a magnifier effect and is not good because they get damaged.
From what i can see you have some pictures in your diary,whit some wet leaves.
This might be your problem
Good luck 👊🏽🍀
Solche Flecken machen mich immer misstrauisch, haben sie vielleicht noch ein Bild von der Blattunterseite?
Klar, kann ein Mangel sein, aber einen Befall sollte man dennoch ausschließen...
Got to agree with Y0ink,
Look at this
growdiaries.com/diaries/129781-grow-journal-by-keepongrowin
then this
growdiaries.com/diaries/129781-grow-journal-by-keepongrowin
Notice how the lower left leaf has water in the same spot as where the new yellowing is.
I think it is also a bit of light burn caused by the water droplets turning into mini prisms, magnifying the over head lights into little lazers.
My roommate burned my g13 Maltezerz by doing the same thing, but hes not a grower and does not know.
I'd also recommend a bit of CaMg, I see other bits of discolouring in between the flat sections that are separated by the veins on the leaf.
But this could be more superficial water droplet lazer prisms discolouring it.
I'd recommend listing your PH and EC/PPM if its relevant.
I don't see any of that in the diary nor what your feeding it.
Happy Growing!