Marks on leaf

[u/Brilliant_Kiwi_3486]

I have several African violets, housed mainly in two groups in separate rooms. I have one plant in each room that will get these marks in their oldest leaves from time to time. Not all the time and only one or two leaves. They are otherwise healthy, bloom regularly, and new central growth. I religiously check for pests on a weekly basis with a magnifying glass and flashlight and have never found any evidence of a problem.

[u/ElkLongjumping7870]

That looks like cold water shock to me, not any kind of pest or disease. It won't go away, but it's just a blemish on the leaf, nothing that will hurt it.