Tomato leaves have weird white lines

[Insxncere]

Hello! Growing tomatoes in a hydroponic setting (perlite), leaves are curling upwards (almost closed) and the lower leaves are having this whiteness on the bottom then dying. Pictures enclosed below. I don’t think its powdery mildew, its not fuzzy and it follows the veins in the leaves. I'm using a generic synthetic vegetation hydroponic solution.

[imafan26]

Do you have a magnifier? I would look more closely at what is on the bottom of the leaves. I have never really seen that, but it does not look like a nutrient deficiency. It looks more like a pest.

[applestar]

I’m thinking the same — mites infestation would be first suspect in my mind.

Also, is there any sign of leafminers?

Another possibility might one of the other fungal issues like gray mold? Wait no - tomato leaf mold? …but I agree with @imafan — this seems more like a pest. I feel like I’ve seen it before which takes me back to mites or leaf miners.

In any case, leaflets that have gone crisp should be removed, and entire leaf if more than half gone. And be sure to practice good sanitation so as not to spread if mites (or fungus).

[Insxncere]

Do you have a magnifier? I would look more closely at what is on the bottom of the leaves. I have never really seen that, but it does not look like a nutrient deficiency. It looks more like a pest.

here are some more pictures. I carefully stared at them for a while, didnt see any movement or bugs. also there are no webs.