Sick plant with browning leaves? Possible cal/mag deficiency?

I have a small DWC setup and using flora micro. My other plants look decent but for some reason this one looks pretty bad and was hoping for some help. I did order some cal/mag and it should be here tomorrow.

Ah the multi bucket of doom! Whats your PM/PPM and temps?

Go easy on me hahaha 1st timer. Out of the faucet i get 44 ppm using a TDS EZ. My temp is right around 70. All other plants look healthy. It's just this one.

I forgot to ask if these were all the same strain or just random stuffs? Anyways ya 44ppm out of the tap is awesome, but def needs some cal/mag. Those leafs are roached, but at least the rest of the new growth looks great. The calmag should keep the others from suffering the same eventually.

Yes same strain. It baffles me how one is perfect and the other may have cal mag deficiency. Either way I should have some cal/mag today and I will add. Thanks for the advice!!!

Looks like nute splash burn from splashing on leaves.

I'd go for cal or mag too just add decent dose an u see them pick up. Keep eye on new growth for spots forming as if they do you need add more cal / mag

You need to use more then just the micro. You need to add at least the bloom. Not sure if this is your issue but it's def not giving the plants all they need. As far as multi plants in one system. As long as they were from the same mother (assuming you got them as clones) you should be fine. If they were grown from seed or taken from random mothers you're going to have issues. IMO.