you could find out what’s in FFOC and then try to make your own blend with better ingredients. That’s what I’ve done with soil mix and ferts, just start with regular cannabis-industry stuff and then gradually replace them with my own choices.
I see soil mix broken into 4 components: peat (or coir), compost, aeration, and nutrients. I like about 30% aeration, 20% compost, 50% peat. I’m sure FFOC is similar.
Aeration is perlite or rice hulls. I’ve tested some peat/perlite base mixes to see which one I like best (the coarser ones), I use local compost and worm castings for the compost part, and then pick my favorite fertilizers (blood meal, fish meal, guano, kelp, alfalfa, etc) and add 3-4 tablespoons dry nutes per gallon of mix to start.
edit, here’s another example, Aurora tells you what’s in Roots 707, you can see their choices -
base - peat & coco fiber
aeration - perlite, pumice
compost - Composted forest material, worm castings
nutes - Bat guano, soybean meal, fish bone meal, kelp meal.
http://www.aurorainnovations.org/formula-707.html
FORMULA 707
INGREDIENTS
Peat Moss, Composted Forest Material, Perlite, Coco Fiber, Pumice, Worm Castings, Bat Guano, Soybean Meal, Fish Bone Meal, Kelp Meal