go to the local plant or hydro shop with cash. for 20 dollars buy a bottle of fox farm grow big and for another 20 get a bottle of fox farm tiger bloom. you will not be sorry. but you will be if you fuck up using miracle grow. you can use any nutes really but you wont get the maximum effect. fox farm is the best as far as im concerned. dont forget that you soil mix is mucho importante also.
heres my recipe. 1/4th perlite, 1/4th vermaculite, 1/4th seed starter soil, and 1/4th sphagmnom and pete moss mix. use this in 5 gallon buckets with fox farm nutes you will be happy.
i didnt switch to using these till my third grow now im smacking myself for not changing over sooner.
what you got for lights? watering soil? or is it hydro?