Can't go wrong with pool filter sand at $10 for a fifty pound ba. It's all I use for my loaches and cories.... It's really all I use for everything. Even my big planted tank is dirt under a blanket of pool filter sand. If you live near a pristine river you can find the full spectrum from river stones to gravel to fine sand at elbows and river bends in large deposits. This is safer for FW aquariums than beach sand. Just bake it at 350 degrees for 20min and let it cool before you use it. I refuse to pay for anything like that. You save incalculable time, effort, and energy sourcing things from your backyard. Just pour a little muriotic acid on questionable stones to make sure they aren't reactive. Most wood can be boiled but stay away from walnut. Wood that's already in clean natural water is definitely better as it's already saturated. Again it's best to boil it first. I use oak leaves instead of catapa that's crazy - it's crazy paying for any of it! I try to only spend money at my local fish clubs. If you're at all handy just build everything yourself. Not only is it cheaper but the customizable options are exponentially greater than anything from some corporate entity