What is the difference between Miracle-Gro and other commercially available
fertilizers and hydroponics nutrients?

Most of the fertilizers readily available are very general purpose mixes
that do not work well for all types of plants.
Most commercially available fertilizers are meant for fertilizing plants
grown in soil and do not contain all the necessary trace elements.
Spectialy fertilizers contain all those trace elements, and are also made
to be very soluble so that the plants can easily uptake the nutrients from
the watering solution. Those other fertilizers will work to grow plants
but they cannot compare to the results you will experience with our
nutrients. Most commercially available fertilizers are like junk food for
your plants giving you quick results that do not last very long.
If you want to grow right then use the right nutrients.
Miracle Grow is not for dichotomous short day resin producing plants.
Tomatoes & flowers are not in the same group as Marijuana plants.
That is why you do not use Miracle Grow or anything that has the name
Miracle Grow in it for Marijuana period.