Substrate

Not breaking the bank? Having some finished homemade compost on hand really helped me making soil last week. and when I filled 4 100 gallon pots 2 years ago. i thin some of my old raised bed soil from my garden was composted down and reused. I do both regular composting and worm composting. I didn't want to go to the store an buy peat moss since up as only filling up a few 5 gallons. so added just a bit more compost than normal and extra perlite to balance it out and keep it form being to heavy. Check out my soil recipe diary for some ideas. Going to depend on where you live and what's best option. I would find a reputable local compost business and get a yard and that would hep you make several batches. I can get peat moss for 3.8 cu/ft. the home improvement store has 1/cu ft bags of lava rock for or so. usually fairly large size so good to break them down a little.. but depending on where you I've their may be an abundance of stuff like that. pumice is the best option but pretty pricey for me. Get several sources of calcium if you can and extra silica.