cal mag deficiency or...????

Check the pic....

The leaves are all lowers from 6 out of 8 plants. The symptoms dont show on any upper fans...yet.

Look like cal mag deficiency?

Looks a bit like too much residual fertilizer in the soil. It could definitely be a calcium deficiency but I would bet on too much fertilizer. Do you grow in soil? Do you feed often? More information would be helpful. =)

Looks like magnesium but it could also be just seasonal drop.