Catappa bark comes from the same tree as Indian almond leaves, and carries a lot of the same benefits. It releases tannins as it breaks down, which isopods and springtails will graze on, and it holds up as a nice piece of natural hardscape in the meantime.
 
Works well in bioactive terrariums, paludariums, or shrimp tanks. Each log will vary in size and shape since this is a naturally collected product.