My Big Kush leaves appear to be more light green t...

They look good color wise, don't worry. But they do look kind of small; there's a few thing that you can improve. First: watering. Are you really giving them 600 cc of water a day? That's too much, a seedling of that size need a cup of water (200 cc) every 4 to 6 days. When you give them too much water, then you literally drown the plant, preventing it from taking oxygen, slowing growth down to a crawl. Second, don't feed more than once a week. Good luck