be careful of your temps.
i had heat issues using a small space with CFLs, they give off enuf heat that it will add up.
try to stay 70-80 F

and Im also using MG soil and no problems related to that.
make sure theres plenty of perlite mixed in tho, i added about 30% to each pot.
mine are doing pretty well after some problems early on. Heat related.
you can see my growlog for more if ya want

Good Luck!

Rock.