Do you water till runoff, or give a set ammount per watering?
Same with feeding...runoff or not...?
Are you letting the pots dry between watering/feding? Cannabis prefers a wet-dry cycle. If the roots are constantly wet, it will smother the plant and lockout will begin. If the soil doesn't need water, don't water.

Yellow leaves with darker green veins is a sign of magnesium deficiency.
To treat the magnesium def.: Thoroughly mix 1 tsp (teaspoon) epsom salt (or magnesium sulphate) per gallon of water, raise the lights a bit, and spray the leaves, don't spray the light(s). When dry, spray with clean water to remove any salts left on the leaves. Once leaves are dry, lower the lights back to 'normal'. Repeat in a few days, but only if necessary.

Could also be the plant getting used to the new soil and schedule. If it's transplant shock and PMS (Pre Motherhood Stretch) it'll usually be ok within a couple of weeks of initial symptoms and they should start filling out and uptaking nutrients.

These are the most likely causes, but not having pictures makes it harder to pin down.