Ca deficiency?

No not calcium deficiency, but nitrogen toxicity. You have burned leaves. Calcium deficiency will initially present as small brow dots/spots.

dark inteveinal looks like a p-deficiency, but that should occur at bottom of the plant, first. (mobile nute) P can be locked out by calcium. Have you added a ton of that over time? in a soilless/hydro context all you need is 100-130 ish.. local tap water will have some in it and causes a bit of variance as well is local VPD as far as what concentration you need of each nute, but it's a good ballpark for most people. if in soil, this info isn't too useful because there are so many unknowns about what came pre-charged in the soil in addition to your fertilization. P also has a bidirection stimulative relationship with Mg.. if you added extra Mg lately but also didn't up dose of P with it, that too could cause a p-deficiency symptom. Good thing is it is progressing fairly slowly? So, let it present itself a bit more to be certain. Reference a simply leaf chart and Mulder's Chart (informs about antagonistic vs stimulative relationships between nutes) to make an educated guess.. that's all we ever have.