If I were in a situation where I thought it was calcium deficiency, I'd be anxious to change it and start grabbing some egg shells and ashing them on a fire before grinding them to dust, after having bashed a calcium vitamin supplement into powder with a hammer and watering that in (a fraction of one per plant).
In addition to pics it might help if you describe your soil and how well it drains, how often and how much water the pictured plants receive, and how much and how often (and the type) of fertilizer they're receiving if any, and if you are doing foliar feeding with it or only straight into the soil. Also examine the soil surface for traces of fungus growth, and insects there or on the leaves, and the condition of the plant's stem especially at the base, soil level.