What's the best substrate?

[Ruby]

If you check various sources for similar products, you can probably find "bulk" sizes, & you can compare costs that way too, assuming you enjoy math. Generally speaking, bulk sizes do save you money, & I tend to shop that way too.

What do you guys think about this?

https://www.amazon.com/gp/product/B0...DKIKX0DER&th=1

It's made for gardening, But it doesn't have any chemicals and they flushed out any extra sodium.
I think I've only seen one person use this for reptile bedding (Benjamin's Exotics)

It looks very similar to Eco Earth.