Cal Mag or Phosphorus Deficiency’s

Was super soil mix but had Gnats & used peroxide a few weeks ago. QB 260 lighting. 19 inches away from canopy. Have fed twice with Sensi Grow A+B & have also sprayed with Epsom salts. New growth on tips is yellow & leafs keep getting lighter in color. 18/6 lighting schedule. First pic is current Second is 3 days ago

Locked out on Sulfur or iron.