cal/mag pry some p or k deficiency feed only water for a few. back off on your nutes by 50% or so. im guessing you jus started your nute program? those light green spots and weak stems and browning are all problems. i think you are overwatering because of their droopiness causing nute lock out.. slo growth and weak stems?
soil should be allowed to dry out for and hr or so between waterings.
tell us about your nutes and watering habits..also need to know soil type and planter size. help us help you
mixing about 5 cups of tap water into the pure water you give your plants will take care of the cal/mag def. enuff trace of cal/mag is in most tap water to take care of the plants needs.
a second thought i had was are u giving the plants chlorinated tap water?