keep that soil moist until they start showing their first set of true leafs.
People hate on MG because they simply cannot grow!
I'd advise you to pick up some Sta-green soil and a box of MG tomato granular fertilizer. Good for if you are on a budget and produces some nice buds. Just go 1/4'th strength and build your way upp every 2 weeks. I have found nuteing at 1/2 strength was too much. 1 1/2 teaspoons every 2 weeks worked good with the sta-green soil. Just remember to flush 2 weeks before you harvest. 1 week seem'd to have taken all the chemical taste out of the buds. You'd want to flush BEFORE your bud's start fattening up as if you don't they will absorb the nutes into the buds and it's then harder to leach it out. I've heard boiling roots works to deplete the chemicals out of the buds but have not tried this myself. Heard this from a old grower with 3-+ years experience so they cannot be wrong