Lettuce not looking so good.... :(

[Kona]

I'm a first-time vegetable gardener in soCal, and I've got lettuce growing in some containers. The other day I noticed that some of the leaves had a yellowy-white edge to them, at first I tried watering a bit less, but it didn't seem to help.

Now, I can't tell if it's just me panicking a bit, or if it's real, but I think it's happening to more of my lettuce in the same container and the one right next to it. I have been spraying for fungus gnats recently and was wondering if maybe that had done something as well. (I used "Monterey Take Down" spray)
I've looked up some lettuce diseases, and I'm wondering if it's possibly aster yellows, but I'd really hate to lose this crop so I'm really hoping it's not.

I've posted some pictures here so you all can have a look and possibly help me determine what's going on! I'd really appreciate it!






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Fixed the image codes to dispay
-- applestar

[ruggr10]

I think you are panicking.... they are young, yet.

[Kona]

I think you are panicking.... they are young, yet.

I sort of assumed I was. I did some further reading and it might be an iron deficiency? Also some possible sunburn.
Anyway, I just want them to do well! ><