OP, "they" may say you can't overwater coco, but that's usually referring to after they are fully rooted in the container, which yours are most likely not. At this stage, 3 times a day is excessive and wasteful at best. Those babies look underfed and possibly overwatered (and keep in mind overwatering can affect nutrient uptake).
And unless you're using RO water, don't worry about the cal-mag for now, or use it sparingly if you must.
And this time let them flower at least a month-month and a half longer than last time.
Good luck!