Calcium Reactors

Calcium Reactors are a great way to maintain healthy levels of Calcium, Alkalinity, and all of the major ions in seawater necessary to grow SPS, LPS and even Soft corals.

Calcium Reactors are a great way to maintain healthy levels of Calcium, Alkalinity, and all of the major ions in seawater necessary to grow SPS, LPS and even Soft corals.

Many people think the calcium reactors are primarily for stony coral systems, and this is partly true. Certainly SPS corals require a higher levels of calcium and alkalinity to replace that which is used by the stony corals as they build their skeletons.

We have found however, the soft corals benefit from calcium also.

We like using calcium reactor's for both soft and SPS systems. Calcium reactors are great because they are very low maintenance in the long run. They're much cheaper to use than the typical two-part solutions that you buy. Sure there's a higher initial startup costs, but if you're serious about keeping SPS corals, they're almost a must.

We do have calcium reactors on all of our systems, both soft systems and our stony coral systems. When you are dealing with a large number of systems and tens of thousands of growing corals, you can imagine how great it is not have to use an addttive on a daily or weekly basis to maintain the levels .

How Does a Calcium Reactor Work?

Calcium reactors work by dissolving aragonite, which is crushed rock made of ancient coral skeletons. Fortunately, these skeletons have the major and minor ions present in the correct proportions (this is important) that your growing corals need.

The aragonite is dissolved by using a small quantity of CO2 (yes the green house gas), which is slightly acidic. Mixing bubbles of CO2 in a chamber of aragonite will dissolve small amounts of aragonite. This is then continuously added to you tank (hopefully in the sump) where it stabilizes the pH while raising both the Calcium and alkalinity levels in your system.

Aragonite is basically a type of ancient mineral that's almost identical in composition to the coral skeletons.

The beauty of calcium reactors is that they replace the minerals that your corals need, not only the major ions like Calcium and Magnesium and Strontium, but also the molybdenum, and even many other other trace ions, in the correct ionic proportion.

Ionic Proportions are Important

It is very important to maintain ionic proportions, because if you added too much of chemicals such as calcium they can actually inhibit the amount of alkalinity that can be carried in solution.

So, the way it works is you have a chamber full of aragonite, and and the aragonite is very slowly dissolved by adding the carbon dioxide in the form of a gas. The CO2 is the same that you use to fizz up your soft drinks when you go to McDonald's. If you use a Coke dispenser at the fountain, then it injects CO2. So in many cases, you can buy or get refills using the same cylinder of CO2 from the same source for the restaurants are using.

Where to Refill Calcium Reactors

Even if you buy a CO2 setup online, you will need to get the CO2 bottle refilled locally. Look for a restaurant supply house, and often they can provide the CO2 gas, or you can check the Yellow Pages for air gas company. We use Linde gas in Lilburn GA. They always have a good supply of CO2 ready in all different bottle sizes. But any place that sells CO2 for use in soft drink machines should sell it to you. It doesn't require any special license to buy, even though it is under high pressure. I might be wrong, but I dont think they can ship the cylinder full since the high pressure would be hazardous if the cylinder is punctured.

Filling Your CO2 Cannister

Be careful not to inject excess CO2 directly into you tank as it can act as a fertilizer and help create an algae bloom. The effluent (liquid coming OUT of the calcium reactor) may have some residual CO2 in it. Its best to "blow it off" by letting it drip through something above the water where the CO2 can be exchanged for O2.

We actually run our calcium reactor effluent into our mud filters where our macro algae is growing. That way any CO2 that makes it out of the reactor is rapidly used up by the macro algae, typically Chaeto sp., before it makes it into our main systems. You don't want CO2 to enter you main tanks, as it is acidic and will rapidly lower your pH.

So calcium reactors are a fantastic way to maintain a high pH, and to maintain a high calcium alkalinity balance if you can stomach the initial high cost. They are great for adding back the other major and minor ions that are used by the growing corals, fish, and other biological processes going on in your tank.