The leaves browning on the tips are a sign of overfeeding/nutrient burn. The small spots are most likely Cal/Mag deficiency. Possibly due to ph being out of spec or from excess nutrient/salt build up in your soil. How many more days are left on them? A flush may be needed along with a weak Cal/Mag solution. What soil, nutrients, ph, etc are you using?
Soil: Fox Farm Ocean Forrest
Nutrients: General Organics GO Box
pH: I'm using organic nutes so I didn't buy a ph meter
