Day 8: I've watered the plants with 500 ml water with only a half of Easy Grow Booster Tablets in 4L water (pH: 6)
Day 9: Adjusted the lights to 20 cm for each plant. Weather is cold and rainy for last few days and I feel like plant is not growing. I'm not sure these weak lights will be useful at all. I guess we will see.
Day 10: Watered again with 500 ml solution (pH: 6.3)