HPS could cause infrared over-heat on your seeds and kill them quite fast. So rule of tumb is avoid HPS to start seeds and use floros at 2 - 3'' over the plant canopy to maximize lumens absoption by the plants. Also, push seeds 1'' in the ground so they are covered by soil OR in darkness if you germinate using moist paper towel...(Germinating seeds in darkness is what gives the nicest results) Keep soil moist but NOT damp. Keep em groing under floros till they are 2 weeks at least, earlier is too risky and could burn the seedlings causing stress and plant stunts...

Hope it helps!

Happy Growing & Good Luck! :thumbsup: