For deficiencies
What kind of miracle grow? Most have way too much nitrogen. And you shouldnāt really be feeding a seedling anything anyway. How old and how many nodes does your plant have? Or full sets of leaves, the node is the place on the main stem where the leaf stalks (petiole) attach to the stem.
Even if your growing medium is completely free of nutrients, like a pure coco coir, peat soil-less mix, or even plain pHāed water in hydro, you donāt really need to feed your seedlings until they have about 5 nodes. The the cotyledon, also sometimes called the āembryonic leavesā, you can kind of think of them similar to a egg yolk, in that it is a stored amount of food, everything the young developing organism needs until it has developed enough, roots established enough, to survive on its own, and so this is why a seedling doesnāt really need any nutrients until it has reached this state/size of growth, which also indicates a well developed root system below ground that can then be healthy enough to take a decent dose of nutrients.
~MacG
Probably the biggest reason would be the proportion of nutrients, none of them, even the closest one ā miracle gro for tomatoes, doesnāt have exactly everything the cannabis plant needs. Cannabis really loves higher than normal phosphorous, calcium and magnesium levels, in proportion to nitrogen, than that of tomatoes generally, and then there is the argument on top of that they donāt use the best forms of the macro nutes, using a lot of urea nitrogen, and some claims they are also high in some undesired metals.
Latewood might like to add more reasons, but these are some of the most common Iāve heard, off the top of my head.
~MacG
OK Letās get to the basics. You used the wrong soil, so first off do not add any nutes to your water except PH corrector. I did the same thing to my jacks on my first grow. I put 2 tlbs. Of peroxide in 1 gallon water then I PHed my water. I watered my plants then let my soil dry out like 4 days. I did this for 3 weeks. Then I started my mutes at 1/4th strength for the next watering. Watch your plant, now you can start raising your nutes slowly. Fox Farms Ocean Soil is really good. But always remember you have nutes in your soil unless you mix your own.
Donāt panic you really donāt want to flush unless itās the last resort.
Not feeding until veg but I figure there have to be nutes in the āSeed Starting MG potting mixāā¦Iām a noob but obviously havenāt started feeding yet Iām on day 6 of seedling working on my second nodes still
Wellā¦Iām not going to be upset with the mg my seedlings are very bright and strong without any help from a fanā¦until I picked one up yesterday. As soon as I slightly over watered, in my opinion, the yellow begins to fade back to a bright green. Iām pretty sure my awesome luck has been due to the genetics from ilgm because being such a noob and making so many mistakes they should I be dead 
I hear bubblegum is a good tough strain anyway
My ph tester also test fertility and the Seed Starting potting mix from MG is off the chartsā¦idk what this means though
If I didnāt say it before thanks for helping me out
do.ob 
I advise people not to use Miracle Grow; So, I advise you to look into what āWillā here stated; Or post a āsupport /ticketā. This will give me an idea what you are doing with your grow, and I can try to give you better advice.
The reason is; MG is not formulated for optimum Marijuana growth. By using preferred organic soils, and supplementing them with the proper additives; You can obtain higher yields with more potency.
MG is a good, generic, fertilizer.
Put it on corn, tomatoes, azaleas, geraniums, petuniasā¦ph high or low loving plants.
Iāve grown pot with itā¦it worked.
But there comes a time you may want more than āit workedā.
Most of the contributors here want more than āit workedā, leaving the feeling you could have done more.
I know I want heavy, juicy, stinky, sticky, smelly, potent and Dopeyā¦The seven dwarfs!
I want what I canāt find or afford. Hopefully a designer fertilizer will get me there.
stuck the seed in some mg seed starting potting mix mixed with 30% perliteā¦and watering with spring waterā¦Iām really not worried anymoreā¦ lol I just posted my issues with mg here for fellow grower that may decide to use the āSeed Starting potting mixā thatās trying to give my day 7 now seedling nute burnā¦ak47 and sour D are doing pretty good in the mg atm thOugh. Only change is the bubblegumā¦ Iāll post pics
Atleast itās only water pedals other than that she looks healthy green
Problem with mg potting mixes is most are designed to release nutrients overtime usually via watering a seedling does bulk of itās growing at very start off of stored energy in the seed itself it does however drink. As it drinks it takes in nutrients which is where good or bad things start to happen I use peat pellets to start seeds or rock wool by 7th day from sprouting I usually have 4th node starting and roots visible I still leave it add a very tiny amount of LK to water and keep it moist. When roots are shooting out every where I put it in a pot first dusting roots with myco or great white then water by next water she is hungry 
When my water pedals turn yellow like that I remove them so they donāt suck nutrients from plant that is formerly in dirt, since they arenāt fed at that young, but thatās just me I donāt know if any one else here removes them when they are yellow
Great advice donald
Definitely using rockwool next time
So this is normal?
define normal? the first fake leafs die yes they yellow because the plant is pulling nutrients out of them to fuel more growth if the new bottom leaves show yellow it isnāt normal itās a hint shit is going to need to be adjusted.
@Donaldj is right, first fake leaves (water pedals) will naturally die off as the plant gets older it will suck the nutrients from the pedals to support the new healthy growth as well as help fuel the growth, if any of the first true leaves or any thing after that yellow she will show some thing is wrong and needs to be adjusted. So yea that is normal for a plant to do that buddy