You should ph at 6.5 give or take. Go 18-6, no need for 24. I wouldn't worry when they so little.
Some appear to be stretching a bit. Also get some air blowing around them. Rotate the cups. around as some are turning for light.
With cfl, better if lights are sideways.
Also, you should not be watering daily. Let them dry out. When small, I wait for the soil to pull away from the sides of the cup before watering.