text: The Reef Ball Foundation manufactures reef balls for open ocean deployment in sizes from  in diameter and  in weight. Reef balls are hollow, and typically have several convex-concave holes of varying sizes to most closely approximate natural coral reef conditions by creating whirlpools.  Reef balls are made from pH-balanced microsilica concrete, and are treated to create a rough surface texture, in order to promote settling by marine organisms such as corals, algae, coralline algae and sponges.
  Over the last decade, research has been conducted with respect to the ability of artificial reefs to produce or attract biomass, the effectiveness of reef balls in replicating natural habitat, and mitigating disasters. The use of reef balls as breakwaters and for beach stabilization has been extensively studied.