What is a Calcium Reactor?

How a Calcium Reactor Works

  1. Calcium Reactor - Pressurized chamber filled with calcium based media. CO2 and aquarium water are mixed together inside this chamber. This results in an acidic pH which will then melt the calcium based media enriching your aquarium water with calcium and alkalinity.
  2. Input Water Line - Supplies the calcium reactor with aquarium water.
  3. Dosing Pump - Pushes aquarium water into the calcium reactor. Feeding a calcium reactor with water can be done a few different ways such as using a submersible powerhead or gravity siphon into the reactor. By using a dosing pump in the above pictured fashion, you can ensure the reactor will not run dry.
  4. Pressurized CO2 Cylinder - Stores CO2 gas for injection into the calcium reactor.
  5. CO2 Regulator - Reduces output pressure from the CO2 cylinder allowing for consistent dosing of CO2 gas into the calcium reactor. The electronic solenoid attached will allow for automated CO2 control with the use of a pH controller.
  6. CO2 Gas Line - Carries CO2 gas from the CO2 cylinder to the calcium reactor.
  7. pH Controller - Controls the output of CO2 based on pH of your effluent water via the electronic solenoid attached to the regulator.
  8. Effluent/Output Water Line - Carries calcium rich water from the calcium reactor back into your sump oraquarium.
  9. Drip Cup - A cup or container installed on your sump that will collect effluent water before it enters your sump or aquarium. This allows you to monitor the pH of the effluent water. Some calcium reactors have a pH probe port on the reactor itself which will allow you to monitor pH inside of the reactor instead of using a drip cup.

How does a Calcium Reactor Work?

In a reef tank, calcareous organisms like corals and clams along with calcareous algae, such as coralline algae, utilize the calcium dissolved in the water as one of the components to build their skeletons or shells. To keep a constant level in our reef tanks we need to supply calcium into the water column. One of the ways to accomplish this is the use of a calcium reactor.

A calcium reactor, in conjunction with a CO2 system, dissolves calcium-based filter media inside the reactor to replenish calcium and other minor elements in your aquarium water. For tanks with a high calcium demand, a calcium reactor is an invaluable tool that eliminates the need to dose 2-part calcium/alkalinity supplements.

Some hobbyists have the misconception that setting up a calcium reactor is difficult. In reality, nothing could be further from the truth. Sure, they might take a little time to setup. But you're a reef aquarium hobbyist—patience is clearly a virtue you already possess! 

Read How to Setup a Calcium Reactor>, watch our videos (AquaMaxx CR-1 Calcium Reactor Setup Guide and Calcium Reactor Components) then set aside a few hours to get your own reactor up and running. If you have questions, contact us! We're here to help and tech support is always free.

The most popular brands of calcium reactor media we carry also happen to be among our personal favorites: CaribSea A.R.M. AragoniteTwo Little Fishies ReBorn Coarse Aragonite and D-D ROWAlith C+.