Advertisement I have been mixing my own substrate and changing it a little each batch to improve it. This is the mix I have been happy with for a year or so. It seems fussy with all the rinsing, baking etc., but my losses are almost 0 and all but 1 mature species have produced pedelings (I most likely had pedelings there but also isopods and I never saw pedelings - you do the math ). This isn't the only substrate recipe that works, but this is the one that works for me. I mix it 30 gallons at a time, so 10+ gallons of each portion and then about 1/3 gallon of calcium. I know that isn't mathematically accurate, but I'm an artist not an engineer. I keep it moist to the point you can almost squeeze a drop of water out of it, but you can't. If you put a handful in a paper towel, the paper towel shouldn't have an obvious wet spot. I stir through it when it is not being used to prevent anaerobic bacteria and I add springtails to each new set up. MILLIPEDE SUBSTRATE MIX 33% COIR: It holds moisture and texture better than anything else I have found. Great for tunneling and making molting and birthing chambers. Color lightens as it dries making it a good indicator of substrate moisture content. 33% LEAF PORTION: Green Envy Leaf™ compost: (Or any other ORGANIC leaf compost). I bake it at 250° for two hours. Any bagged product may have plastic and metal pieces in it, so I go through it thoroughly. This compost makes up about 2/3 of the leaf portion. Leaf Litter: I rinse in water; then I let the leaves air dry. After they dry, I bake them for two hours at 250°. I cover the pans (to prevent flyaway leaves, for safety sake) with foil (shiny side out to reflect more heat). Then I crumble them into the mix. (I also add leaves on the top.) I use all or mostly oak, but also small quantities of apple, beech, birch, hickory, maple, rose, viburnum, walnut and other hardwoods. This is the other 1/3 portion of the leaf portion. 33% WOOD PORTION: Traeger Oak Pellets: Since these are very small chips, they decay more quickly than other wood sources. I soak them first. They increase 3 X their volume when soaked. Anything to add variety can’t be a bad thing; possibly adding trace nutrients. Aspen Shreds: I think this adds a good texture to the overall mix. It also decays quickly. (If my enclosures become too wet, I add aspen to help dry them out.) Hardwood: If close to decaying, I put apple, cherry, hickory, maple and oak in my pressure cooker at 15 pounds pressure for 45 minutes. It should crumble nicely. I use both light and dark rotting wood, but I choose only wood that had isopods and others living within it. If not close to decay, I run the wood through a small chipper reserved for “millipede safe” woods only. I treat it the same as I treat my leaves: rinse and bake at 250° for two hours. *Each of the wood components are of different sized particles and so all break down at different time intervals; adding a “time release” characteristic. By that I mean each source will become available for food at different periods. 1% CALCIUM ADDITIVES: I mix: Ground Cuttlefish Bone, Bird Grit, Oyster Shell Flour, caliche, egg shells (crushed and baked at 200˚ for 20 minutes). I also crumble shed skins from healthy reptiles into the mix. I add this to the mix and I also sprinkle it on the substrate about 2X a month.