I'm guessing pH issue related to water pH in and depleted pH buffer in the soil.

Here are a few suggestions.

1. Don't add any nutes if you are using FFOF. Perhaps a little phosphorus boost in flower at week 4, 5, 6 but that's it. 1/8 strength.
2. If they've been in those 2 gallon pots for more than 4 weeks up-pot immediately to 3 - 5 gallons.
3. Get a proper pH pen. The test kits are pretty inaccurate.
4. Get pH going in right - between 6.2 and 6.8.
5. Give a little molasses but not in conjunction with phosphorus.
6. Don't be tempted to through chemicals at the problem. It is likely to make it worse. Start with the transplant, a little molasses and straight water. Give it a week and see where they are. Also note that the damaged leaves will not recover. For signs of recovery monitor new growth.

Nice job filling out the form. Smart. May people skip this step. It helps considerably and motivates others to help you!
bigsby Reviewed by bigsby on . Sad Leaves What is your experience level? (first timer, novice, experienced...) Novice, first time for indoor. Your Equipment: .1) Type and wattage of lights. (MH, HPS, CFL's, tube fluorescents, LED's) 1x 150W HPS cooled with 4" duct fan, 2X 42W CFLS .2) Distance from tops? about 12" .3) Reflector type? (cool tube set-up, bat wing, enclosed reflector, bare bulb...) Enclosed reflector .4) Is there a consistent fresh air supply? Yes .5) Do you have an exhaust fan and a circulation fan? Yes .6) What Rating: 5