Slow growth even though healthy looking plant. Sus...

1 L/feed is too much water for such a young plant. With living microbes in the soil, growing organically its essential to keep the soil moist and not let it dry out as it will kill most good bacteria for your plant. But at the same time your roots need oxygen and especially in soil it doesn't tend to dry as fast as other medium therefore lifting the pot as your are doing is a good trick. Your doing a good job your seedling looks healthy 👍