I had trouble at first with this also but I talked to a couple of local grow houses around my area and this is what i do now:
I soak my cubes in ph balanced water for a day
remove from water and put into my little plastic grown tray (with lid)
place a seed in each cube add a little water (ph balanced) put lid on and then I cover it with a dark towel and sit on a heating pad.
then once a day there after I open it all up to give air and make sure all is staying wet. and usually in 4 days I have sprouts.
I then move the sprouted ones to a plastic tub I have installed a florecent light in and also covered the sides and top with mylar reflected sheets & and a very little fan is built into on side. I light them here for 17-18 hours a day.
Ive included a couple of pics of the tub I use it is green and dark
my grow trays fit inside of this tub easy, and I leave the lids on even inside this tub until the seedling gets to tall, by then they usually have a few little roots coming out the bottom of cube, they are ready for the farm. I move them to blue lights and bigger buckets.
this works for me, because each seed does its own thing at it own rate and I can move them independently as needed.
hope this helps or gives you an idea (planets a seed) of your own.