yellow/brown tips and some leaves dying/turning yellow

hey so this is my second grow, so i have some tips of my leaves turning yellow aswell as a faded green around some of my leaves this time around im growing photos so i know it may be a bit different from autos but ive always gotten good advice from here, i feed every 3-4 days (until its dried out and light to carry) ive been just feeding silica in spring water as im in a pre-amended soil, im using roots organic lush as i had success with it last time, so yeah if you guys have any advice or help id really appreciate it