I keep mine on 24. What I use are the low watt (13) / 100 watt output "green energy" bulbs. Keeps my meter from spinning like a Frisbee on meth. Three bulbs seems to be more than enough light in a 10X10 room. Bonus is the bulbs have a 10 year life according to the package and guaranteed.
This is answer my question, I have my one seed under 18 hours light since 25th January, it is just coming to the 3rd set of leave,roots appearing through bottom of pot.I think to transplant to a bigger pot in a week , I want to delay flowering till its hopefully a dwarf conifer size and bushy, then take outside gradually increasing the natural sunlight hours knowing that it starts to flower, as I read on countless forums. This is my
first time with lights using a 50watt Led.