when a plant is calcium deficient, the margins tend grow at a slower rate than that of midrib or center portion of the leaf. thats why you tend to see distortion with calcium.
we can infer its not nitrogen because nitrogen is mobile and begins at the bottom of the plant and moves towards the top. we can infer it is not magnesium because mag also shows up on older leaves first, it also tends to show up in the leaf margins first as interveinal chlorosis.
this imo is the best flowchart for deficiency symptopms. keep in mind some of these symptoms can also be caused by PH etc.
i dont think anyone here is claiming its 100% calcium deficiency, or at least i am not. it just seems to strongly resemble it.
IMO you should take stock of what exactly you are giving the plants using that website i linked. your fertilizer bottles should have all the necessary information. use
saltmix.xls or that website i linked.