Using Miracle Grow soil, you don't want to add any nutes for about a month, perhaps a tad more.
Why aren't you using tapwater?
Raise ph to between 6.3 and 6.8.
Early in veg, CalMag not necessary.
I use Fox Farms, and suppliment with molasses. Has plenty of calcium, and is loaded with carbon and micro's. (plus acts synergystically with the nutes)
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Molasses info
Despite the recommendation in the second link, adding 1-3 TBS per gallon creates a lockout condition from lowering your ph and likely micronute overdose. (or it isn't as extreme when used outdoors?) Perhaps this is the ratio for a month, or theirs is watered down? I've been using Grandma's unsulphured (non-blackstrap molasses) at 1/4 to 1/2 tsp per gallon, twice a week, in flower, with great results so far. (replaces my CalMag and Sweet) I just started using it in this dilution in veg, too, but will reserve opinion till I'm certain of results. Closely monitor your runoff ph if trying this, until you get used to it's effects.