Reactors 101

Calcium Reactors
Calcium Reactors are an amazing addition to any aquarium, both big and small. To some people it might appear as if Calcium Reactors are a very technical piece of equipment. They are however very easy to operate and maintain for even the beginner hobbyist; with nearly endless benefits. For a Calcium Reactor to function it needs the reactor itself, a CO2 canister, a solenoid/regulator, feed pump, reactor media, and a pH probe/controller is recommended.
With Calcium Reactors the reactor body is filled with aragonite, which is crushed coral. Aquarium water is pulled usually from the sump and pumped through the reactor media along with pressurized CO2 (from the CO2 cylinder). The CO2 drops the pH level inside the reactor chamber to an acidic level, causing the aragonite to dissolve and be slowly dripped back into the aquarium. The reactor knows when to function based on the bubble counter attached to the reactor body.
The addition of a pH probe/controller is recommended because they are basically like a fire extinguisher. They help ensure that the pH level inside of the reactor does not become too acidic, and is functioning properly at all times. In the event the level drops too low, there are ways to set them up to notify you. Most reefers even purchase Apex units as an extra safeguard. Apex units are capable of monitoring the pH level of inside of the reactor and shutting down the reactor should any costly pH fluctuations occur.
Calcium Reactors are much more than just calcium though. The aragonite, or crushed coral inside of the reactor, also releases many valuable trace elements when it dissolves. Calcium Reactors are one of the most important pieces of equipment when it comes to keeping a successful reef tank. While at first it appears that these are a rather costly investment, most of the time we see customers spend more on additives over the course of a year rather than purchasing a reactor.
Check out the Calcium Reactors HERE that we sell at Reef2Land. They are a very effective way of ensuring your tank inhabitants, such as corals and clams, have the elements they need to maintain peak health in your reef.
Media, GFO, Carbon and BioPellet Reactors
Media Reactors are exactly as they sound. These items can be valuable additions to any aquarium in the event you are having trouble getting certain aspects of your tank under control. Problems such as Phosphates, Nitrates, or having issues such as “yellowing water”. These reactors can house anything from Carbon/GFO/Phosphate Media to Biopellets.  Depending on what you are looking too correct will result in which reactor you use.
Carbon is best for removing odors, chemicals, and/or discoloration from an aquarium. Carbon has been around perhaps longer than any other media. We don’t generally use carbon, unless it is an emergency. Every carbon has the potential to release phosphates into an aquarium, because all carbon is a chemical element. Even in smaller doses any chemical can still build up over time; because after all we are essentially dealing with containers full of water. Seems rather pointless to rid a tank of one problem simply to create another.
GFO is Phosphate Media, also known as Ferric Oxide. This media is usually extremely reliable in marine systems for lowering phosphate levels.  Phosphate is a nutrient created by the mineralization of dead matter; such as uneaten food, fish waste, decaying plants, bacteria, etc. This is why Protein Skimmers are such a necessity to marine aquariums. They help remove these harmful compounds from aquariums and keep phosphate levels on the lower end. But, in heavily fed or stocked tanks, sometimes a GFO Reactor may still be necessary.
Biopellet Reactors, also known as Solid Carbon Dosing, rely heavily on the aquariums ability to fend things off on their own. This is why Biopellet Reactors, as well as Zeovit Reactors (mentioned below) are two of our favorite additions to any tank. Biopellet Reactors colonize nitrate laden bacteria. This bacterium transforms ammonia to nitrite, and then nitrite to nitrate. The nitrate is then either removed through water changes or natural filtration such as macroalgae, live rock, and/or live sand. The addition of a Nitrate Reactor can also be used to control tanks with more problematic nitrate levels (more on this below). Once the bacteria established on the biopellets has finished its life cycle it is then removed from the tank by your protein skimmer.
With biopellet reactors we strongly recommend running the outlet of the reactor as close to the intake of your protein skimmer as possible. At Reef2Land we plumb the outlets of the reactors into the skimmer pump intake. This helps ensure that any effluent (waste) from the bacteria will be filtered from your aquarium to keep your reef members happy and healthy.
Nitrate Reactors
Nitrate Reactors are a remarkably dependable way of keeping harmful nitrate under control in a reef tank where the levels might be problematic. Nitrate Reactors work is by combining Sulfur media with calcareous media. This offers a highly effective level of Nitrate Removal. Water flows through these reactors at a very slow rate, by means of a feed pump. The media contained within the reactor can then begin to absorb the unwanted nitrate. To some tanks, that are either heavily fed or heavily stocked, a nitrate reactor can be an essential piece of reefing equipment when it comes to keeping all tank inhabitants healthy and happy.
Zeovit Reactors
Zeovit Reactors are by far one of our favorite additions to any reef tank. Zeovit reactors are somewhat the equivalent of having a giant container strictly dedicated to beneficial bacteria attached to your aquarium. Someone who purchases one of these reactors should be aware they will need to invest a little time (and money) into keeping these little bonuses thriving. If they do, a zeovit reactor will work to greatly control nitrate and phosphate levels. Zeovit reactors work together with your skimmer to control these harmful nutrients. These “bacteria chambers” work similar to a biopellet reactor, only at a much higher level from what we have seen. The also colonize much larger, more efficient, levels of nitrate laden bacteria.
That covers all of the reactors that we carry here at Reef2Land. To see the full line of reactors that we carry, visit our reactors page by clicking HERE. Should you have any questions about which reactor might be right for you, or if you are encountering any water chemistry issues not addressed, please contact us at