Id just be guessing,the fox farm soil is for the M/J plant and has all the Micros and Macros.The Bigbloom is a liquid mix of earthworm castings,Bat shit,and other trace elements.You said you found a good compost?If i were you from experience,I would find a bag of Earthworm castings and Bat guano,mix the 2 but save about 1/4 of the Bat guano.add a bag of perlite.When time to flower make sure you leave enough room to sprinkle in some of the bat guano around your container.Ive done this with GREAT results gives a good organic grow,opposed to MG the reason no MG your grow never goes long enough for the plant to use all of it,and the AMN.Nitrogen will still be in the harvest,thus chitty taste.I know this cause my first 10plus yrs ago i used it and grew ok but it popped and taste really bad.The most important thing for you and your plant is no harsh chemicals,the amn,Nitrogen being 1.