well since you already have the MG soil...all you can do now is damage control..
MG soils contain slow-release fertilizers which dissolve when wet and are also heat activated...so dry and cool...is the rule with MG..
PH is very hard to control due to wide swings caused by the ferts and the peat base of the soil...
you have your work cut out for you with monitoring and maintaining proper ph levels...but...if you are diligent and don't over-water...you can grow some great meds...
you might notice a black ash when smoking bud grown in MG soil...I assume this is the unflushed
fertilizer along for the ride...whether it may be harmful..I don't know...some folks been using it for years with no problems....not me though...it's too easy to hand mix a safe soil tailored to the needs of the cannabis plant...it just takes a little more time and an empty trash can..
now about your germs...they may take up to a week to break the surface of the soil...be patient..
you mention Fox Farms soil...do you intend to grow in Happy Frog,Light warrior ,Ocean forest...or a mix of them? in reviewing comments made by growers about the

line..I see many that blend OF with HF to create a mixture that drains well ....ph monitoring is also very important to
insure your babies get the most benefit from the soil and the fertilizer you choose to use.
best of luck and hope to see your thread in the new growers forum!