Rinse inert gravel or sand in clean water until the rinse water is reasonably clear, unless the product description says otherwise. Never use soap or cleaning agents.

Depth depends on whether it is mainly decorative or intended to support plant roots. A gentle slope works well; avoid excessively deep oxygen-poor areas.

Check grain size, sharp edges and any effect on water chemistry. Fine rounded material is gentler for species that burrow or forage on the bottom.

Gently siphon the surface during water changes without disturbing the entire bed. In planted aquariums, leave roots and established bacterial zones as undisturbed as possible.