Dosing calcium and alkalinity supplements by hand works, but a calcium reactor automates the job by continuously dissolving calcium carbonate media and feeding the resulting solution back to the tank. The Reef Octopus Classic Calcium Reactor line — CR100 and CR140 — uses a reverse-flow design to maximize contact time.
Why a Calcium Reactor Beats Manual Dosing
Reef tanks with significant coral growth consume calcium and alkalinity continuously, and manual two-part dosing means daily attention and the risk of inconsistent dosing. A calcium reactor runs CO2-charged water through calcium carbonate media, dissolving it gradually and returning a steady, self-regulating supply.
Choosing a Size
- CR100 — the entry point to the Classic calcium reactor line, a 4-inch chamber using reverse-flow design to maximize contact time.
- CR140 — steps up chamber size to 5.5 inches for reef systems with a heavier coral load or higher calcium demand.
Setup Tips
- Start with a conservative CO2 injection rate and monitor effluent pH, adjusting gradually rather than dosing heavily from day one.
- Check media level regularly and refill before the chamber runs low, since inconsistent media levels reduce dissolution efficiency.
- Monitor tank alkalinity and calcium weekly while dialing in reactor output for your specific coral load.
The Reef Octopus Classic Calcium Reactor line is available at Marine Concept Supply — order online or pick up at our shop in Wheeling, IL. Shop CR100 or CR140, and browse more reactors.
