Am I dealing with a Calcium Deficiency

looks like it from just looking at the leaves you pictured. I see it in many different herp plants, when they get to much rain water. PH regulated groundwater on regular basis does the trick for me. BUT when looking at the whole plant in picture one of week three i dont think thats your problem but rather it has a problem with getting Mg. It does not only effect new grow when i look at your plant which is importen when deciding for which nutrient defeciency to treat for. Mobile or inmobile. You also have highly purple stems and in all the plant shows signs of all kinda defeciencies. To much water to little nutriens is what it looks like to me and you just flushed :-/