I can post some pics if you want but the calcium def 2 weeks into flower is probably the number one easily spotted and preventable nute issue for us hydro growers.
I start day one with cal-mag too. But ramps up before the flip and then for about 3 weeks in. Start to back it down once flowers start forming.
I would be careful of using both cal mag and Epsom salt. I think you need the right ratio of cal and mag for it to work properly.
View attachment 10115
That's Mulder's chart. You would think Cal and Mag are 2 peas in a pod, but they actually fight each other. If you get them out of balance, both will suffer.
My knowledge is all hydro so take it for what it is worth.