I have been in the horticultural business(landscape,lawn/turf,greenhouse and market grower) since 1982. Been growing pot since 1969. The one thing that you learn from a lifetime of growing plants is that there are many ways to do so successfully! Store bought compost tends to be a far cry from good garden compost, but usually is good(sometimes garbage), just not great. "Compost" and compost materials not thoroughly mixed and broken down and rich ,dark and crumbly can be less than good, even harmful in some cases. It may be too hot, or primarily just household or garden waste without the benefits of a healthy microbial community. Fabric pots can be very beneficial used with the right soil mixes or watering systems. If you have too much drainage materials without enough compost or other organic water retaining materials (like too much peat or coco in a soil grow without plenty of good compost) you may dry out too fast and need to add water and nutrients more often, even daily or more than once daily! Hydro methods will grow plants on "steroids" if you desire that, natural and organic methods will grow large healthy plants as well, perhaps a bit less heavy/large bu a close second with perhaps a bit better flavor (not always as pronounced but more rounded flavor with more depth and subtle nuances. Some plants and pot strains will produce stronger effects when slightly challenged/stressed but may yield far less! Different sources of fertilizers(or more or less of it) can influence flavor and other characteristics of flowering plants. Genetics are most important! Some varieties will only average a couple ounces (cannabis plants) and some varieties may average more or less. I have grown autos now,(only been growing them a three or four years now)that routinely yielded three to four ounces and others that about two ounces was average. Little mistakes with autos will reduce yield because they develop so fast, automatically! When making compost a minimum of a three x three x three foot bin is best, bigger is better! Source as many different kitchen and garden waste as possible and obtain litter or manure from sheep , goats, rabbits (best three!) or chickens and others and add to the mix. Worm castings are great, but better when fresh and not dried out in a bag for six months! I add them to my soil blends. Turn your compost often, and don't worry about PH, yet. Do not add lots of ashes or lime or chemical fertilizers! Adjust your PH, if needed when you finish your soil blend. If using fabric pots in the nursery we "Hill them in" with piles of mulch, leaves , etc. to help keep them more evenly damp/retain water better outdoors. Inside, using watering trays is helpful to catch the water that may pass through too fast(out the sides or bottom) and allow the pot to soak it back up, thus avoiding "dry pockets" in the bags, that can make a "dead" zone for roots if not prevented! Of course, don't over water so that the pots sit in water for more than 10 -15 minutes. They should reassorb all the water fairly quickly or pour off the excess. Chemical fertilizers tend to make"junkies" out of plants, they need constant reapplications, or they may suffer withdrawal! Living soils full of organisms and organic materials feed constantly, and are somewhat bufferred from PH issues as well. Enzymes and other natural processes are helping make nutrients available, by various means without dialing in precise PH readings! Lights, air circulation, LST, topping all play a role in yields of finished bud. I supplement the soil, with applications of fish and seaweed products at times, to supply trace elements and give them a little boost. What's so bad about growing plants with only a couple ounces yield , if they taste good, work on you good, finish quick and you did not have to tend them for hours daily! Anyway, watch out about comparing methods, when so many people report failures , most likely caused by poor soil blends, failure of watering properly, fertilizer problems, lighting issues , ventilation/circulation or too much fiddling/stressing out fast developing autos! Relax ! Smoke a bowl! Try to tweak your methods a bit, try different methods, pay attention to the environment, but relax, in time you will get good results and know why you did or did not, with most of your grows! Happy Growing!