Plant problems - Can't figure it out

[Bearkeeper1]

So most of my plants are doing fine. Looking good, a few spider mites here and there but they're under control, but lately just a few of our plants are having weird problems I cant seem to diagnose from the internet. Hoping someone can give me a hand! I think it's nutrients or PH but my mentor thinks it might be a pest. I've looked at all these leaves through a microscope and couldn't see any living things on them. Any ideas are appreciated. Thanks!

leaves are curling up, just the outer edges are dying on some, a couple look like they were eaten, getting brown spots on some.

 

[nwpassage]

You might be wiser to post this in the pests and diseases sub-forum. This one seems to be populated by a bunch of newb gardeners enjoying life who are scared to death of those pictures. I'd be thinking both, but that's from the newest of newbs.

 

[Robert Celt]

I would say you have one of 2 problems. Most likely problem is a Magnesium deficiency (the yellowing leaves combined with the twisting leaves) Add some Epsom salt to your water and give them a drink. If it is a Mg deficiency, this will solve it. If its not Mg, then it won't hurt your plant.

The second thing is check the main stalk for powdery mildew (white chalky patches). It will damage the tissue in the main stalk that feeds the plant and can cause what appears as deficiencies.

The holey leaves where eaten by something, could be a snail.