I can't find any soils that are free of fertilizers

[Navy]

So I contacted the local wildlife sanctuary about the super friendly, outgoing box turtle I had found.
She said that he was probably a pet, and since he can't be released, I could keep him as long as they get to inspect his living space.

Well, I have build a nice little pen, made a nice little pond and hide, but I'm missing one major thing.
The substrate.
I've looked and looked for soil that isn't tampered with using pesticides or fertilizers, but I just can't find any.
I'm going to need a lot, so the stuff at pet stores is a bit out of the question.

Suggestions?

[Foschi Exotic Serpents]

How much is a lot? If you pick up a few bricks of the compressed and dried coco fiber bedding it will make a LOT of bedding once wetted and it expands. One brick filled a 40 gal breeder a few inches for me and that's a reptile tank where it is wider from front to back than a fish tank so that's a lot of area to fill.

Get a big Rubbermaid tote to put the bricks in, add the required amount of water, leave the entire thing outside for a few days, flip and stir it, and it will quickly dry out. You can also mix some cypress mulch in with it. Cypress also will not mold. Adding dried leaf litter will increase the mini eco system properties of it and you should never need to change it. Especially if it gets some spring tails or other tiny bugs (like what you see in your flower pots when you water them) in it.

It sounds like your new turtle is going to love it's new home

[Navy]

How much is a lot? If you pick up a few bricks of the compressed and dried coco fiber bedding it will make a LOT of bedding once wetted and it expands. One brick filled a 40 gal breeder a few inches for me and that's a reptile tank where it is wider from front to back than a fish tank so that's a lot of area to fill.

Get a big Rubbermaid tote to put the bricks in, add the required amount of water, leave the entire thing outside for a few days, flip and stir it, and it will quickly dry out. You can also mix some cypress mulch in with it. Cypress also will not mold. Adding dried leaf litter will increase the mini eco system properties of it and you should never need to change it. Especially if it gets some spring tails or other tiny bugs (like what you see in your flower pots when you water them) in it.

It sounds like your new turtle is going to love it's new home

I had no idea that the bricks added that much, they look so small in the store.
I have plenty of leaf litter and I'll get some cypress mulch tomorrow assuming I can find it easily.
As long as he's healthy and happy, I'll do whatever I can for him.

I'm also a bit puzzled on whether I should take him to the vet to get him checked for internal parasites or not.

[Jabberwocky Dragons]

Coco fiber bedding sounds pretty good but if you still want to use soil, go with Bacto Topsoil. Bacto is the best brand and it's nothing but pure soil... no sand, no twigs, no fertilizers (in the topsoil). As far as I know, you can't get it at a big box store but a local garden shop should carry it. It's about $7 for a 40lb bag. If you can't find Bacto, Black Kow is a good second choice. Stay away from the generic brands and premium Scotts soil unless if you want rocks and twigs.

[KMG]

I second the Eco-Earth compressed coconut. It does make alot and its cheap. I use it for my Hoggy and its great for burrows. A box turtle would love it. It feels alot like dirt too.

[varnoid]

sphagnum or peat moss is great soil and cheap