The Reef Octopus CR100 4 inch Calcium Reactor is an essential piece of equipment for maintaining optimal water chemistry in a saltwater reef aquarium. It works by slowly dissolving calcium carbonate media with a controlled CO2 injection, continuously replenishing essential elements like calcium and alkalinity that are consumed by corals and other invertebrates.

Featuring a robust 4-inch reaction chamber, this calcium reactor is designed for efficient and consistent output, ensuring stable parameters critical for coral growth and health. Reef Octopus is renowned for producing reliable and high-performance aquarium equipment, making this unit a dependable choice for serious reef hobbyists.

This calcium reactor is ideal for intermediate to advanced reef keepers with established aquariums, particularly those housing SPS corals or a high bioload of calcifying organisms. It eliminates the need for daily two-part dosing, providing a more automated and stable approach to maintaining critical water parameters for a thriving reef environment.