firstly, miracle grow IS NOT 30-10-10.

it is 20-20-20

ive used miracle grow plant food for YEARS and have only had a problem with it one single time, ad that was on a 18" plant that was watered with it by mistake when it was completely dry (never do that with any fertilizer as if the plant is very dry and lacking moisture, it will suck it up so fast it WILL kill it in a matter of minutes)

i use regular miracle grow for veg, and flowering miracle grow for the first 3-4 weeks of flowering, then use only mollasses and corn syrup. if you use any chemical fertilizer, dont forget to cut the stuff off at LEAST 4 weeks from harvest and flush well.