Congratulations on getting sprouts! Light is a funny thing, a light bulb even 1 yr old has half the lumens it once did, I read on here somewhere that 6400 lumens would be decent light. Add a fan, it helps strengthen them, and try to wait til late pm to see if they perk back up. What happens with a plant, is that when the sun gets hot, the plant sends its water to the roots, it is a survival trait. Try putting them out at night- since I know SC is hot at night- letting them stay out til maybe 9 am, then bringing them in until maybe 6pm and taking them back out. If their upward growing stalls, they are putting energy into their root system to aid the top growth. Don't stop the fan and lights while they are indoors, and best of luck!