new growth starting to show yellow around edges

Hello all...i was wondering if any of you could help me out with an issue i have with one of my plants...its the sour og kush...it is 3 weeks into veg. And i noticed this morning there is some new growth of leaves that are coming in with yellow around the edges...my ph is good..its about 5.9 and room temp and humidity are where they need to be...all my other plants in the same room are fine but this one....any help would be greatly appreciated.

soil or hydro?

probably needs a feeding, npk and m.

It is in soil

Your pH is too low for soil! Looks like a potassium/magnesium lock out to me. Add nutrients to your water and adjust the pH to 6.3-6.5, then flush your medium. Have you fed your plants any at all?

Yes i have fed them pleanty...i use the advanced nutrients sensi grow line....along with b-52 ,voodoo juice, pirahna and tarantula