Miracle grow would not be my first choice ladies and gents lol.....but it's a cheap media for someone on a really really tight bugdet that works just fine just needs to be flushed before use like any other growing media,add perlite to soil 50/50 and Hydroton or grow rocks on bottom of planter to drain better till run off is clear.
I was giving you the cheapest possible way to grow 6.00-8.00 per bag vs 20+ for others will give more money for more important things like nutes/amendments,lights, fans etc...I would recommend ffof x light warrior starting out and guano teas or currently what I use in soil grows 5 gal ffof 5 gal perlite 5 gal sunleaves chunky coco 5 gal sunleaves fine coco all mixed together evenly and flushed and with every watering/tea ewc.(earth worm castings)
mex bat guano in veg as they get around 8-12 inches I use both mex bat guano x Peruvian seabird guano to transition into flower and in flower add Indonesian bat guano to the tea mix using all 3 in flower 1 week tea 1 week water alternating and home stretch banana peel tea works like overdrive from advanced nutrients full of potassium. If all organic flush is not all that necessary plus it's hard to burn plants organically, once they have strong roots and are about 12 inches tall.
and I also use extras like cal mag plus cause I use ro water can also use dolomite lime for cal mag,dolomite lime will buffer ph in soil as well as provide cal Mag.
hygrozyme, florolicious plus, coco wet wetting agent, to prevent dry spots in soil/media and maximize plant nute uptake, great white ben bacteria from plant success Before transplant into the ffof and every other feeding with your teas also add super thrive,just to name a few great products that are cost effective give great results and last you.
Again need to add perlite to help it breath/drain better esp if you use cheap soil like Scott or miracle grow that mostly uses mulch in the mix instead of perlite which is one of the problems poor drainage and poor amendments also stays to wet.
if you have extra to spend by all means use better media start out seeds in light warrior then transplant into ffof with perlite and use a simple 3 part nute from any manufacturer or best option go with teas I use sun leaves if in soil but there are many other great ones available
ff chem nutes/bottled seems to be not to expensive but I prefer advanced nutrients 3 part with many extras and mostly do dwc not soil but these are some good products I have used in the past. And if you can afford hid lights go for it and veg under t-5's till about 6-12" tall then switch to mh then flower under hps light.
There are many ways to grow and a media is just a base it all depends what you put into it that will get you different results.
Most important thing is keep ph in soil/media around 6.3 not to worry to much at all if doing all organic with dolomite lime keep temps around 65-75 but under 80 degrees and humidity at 40-60 percent and good air circulation also one of the common mistakes is over watering which is why I like adding so much perlite and grow in smart pots more feeding equals faster bigger growth It won't need water/feeding until top 2 inches are dry. Good luck and hope this helps out a bit.
