Aquascaping will contain products that can be used as decorations as well as functional breeding aids and inexpensive filter media.
1. Driftwood provides nutrients as a food source for some species of plecos, releases beneficial tannins, may acidify water slightly and provides specialized habitat.
2. Lava Rock has been used for years by many old-time breeders for inexpensive filter media due to its high porosity and rough surface providing a suitable medium for efficient colonizing of nitrifying bacteria. Also
3. Crushed Coral likewise has these filtration benefits but will of course buffer pH. Beneficial for hard water species.