when to start adding nutrients to water

So i have a plant outside about a month old i was wondering when to start adding nutrients to the water. Also the nutrients i got are superthrive, miracle grow bloom booster and mag pro if one of these is good let me know and also how much i should use of it and how often thanks!!!

Now is fine to start feeding, I have converted to all organic, so no miricle grow for me (never used it anyways), but, to each their own. Use a well balanced feed for veg like a 10-10-10, or 20-20-20 than lower the (n) when they start to flower, and late in flowering cut out (n) completely.
If you can find a feed with micro nutrients in it as well even better. Feed as directed on the bottle and maybe mix it a bit lighter, til you get a feel for it. The stronger the mix, the longer you should go between feedings, lighter mix you can use a couple times a week to 10 days.