CR100 4 inch Calcium Reactor

The Reef Octopus CR100 4-Inch Calcium Reactor is the entry point to the Classic calcium reactor line, using a reverse-flow design to maximize contact time between aquarium water, pressurized CO2, and aragonite media. As CO2 lowers the pH inside the chamber, the aragonite dissolves and releases calcium, alkalinity, and trace elements back into the water — a largely automated way to keep up with coral demand.

• Best for: hobbyist reef tanks wanting automated calcium/alkalinity dosing
• Body: 4-inch reaction chamber, reverse-flow design
• Monitoring: built-in pH probe holder and bubble counter for tracking CO2 drip rate (pH probe and controller sold separately)

A calcium reactor is the lowest-maintenance way to keep pace with SPS-heavy or otherwise calcium-hungry systems — once dialed in, it needs far less manual dosing than liquid two-part supplements.

Compatible replacement parts: media chamber seals and bubble counters for the CR100.

At Marine Concept Supply, all sales are final. Due to the sensitive nature of live animals and aquatic products, we do not accept returns or exchanges under any circumstances. Please review your order carefully before completing your purchase. No Cancellations.

If you have any questions or concerns about your order, please contact us at shop@marineconceptsupply.com and we’ll do our best to assist you.

We Ship UPS and will send tracking as soon as the item ships. 

Return shipping for any approved warranties are not covered and will be subtracted from the approved credit total.

Restock Fees apply to some products, due to their size or a manufacturer policy.Each product with a restock charge is marked online, in the description.

Please inspect your order upon reception and contact us immediately if the item is defective, damaged or if you receive the wrong item, so that we can evaluate the issue and make it right