Calcium reactors are one of the most novel tools for maintaining mineral balance a reef aquarium with fast growing, resource-hungry stony corals. Like all things ‘made for reef tanks’, there’s a huge range in how much you can spend on a calcium reactor starting from the budget friendly and easy to use Element CA by Seachem’s Aquavitro, all the way to the ‘Rolls Royce’ Deltec Twin Tech which is fully automatic and mostly hand made.
Whether you’re using an injection molded or CNC machined calcium reactor, the concept is essentially the same consisting of a sealed chamber with a recirculation pump and they are not all that different from a canister filter with connected inlets and outlets, with additional smaller hoses for feeding a slower rate of water and carbon dioxide. We may be grossly simplifying the operation of a calcium reactor design, they all mostly do the same thing but the real difference is in the ancillary features such as the quickly removable inner chamber of the Element CA, or the automatic operation of the Deltec Twin Tech.
While there might be a tenfold price different between the budget and the premium calcium reactor models, at the end of the day they both create an acidic, low pH environment to dissolve the calcium carbonate derived from the very same corals that we are trying to grow, and there’s a time and place for calcium reactors of all types. In our latest video we go over the details of these two vastly different calcium reactors, discussing the different sizes of reactor medias, why we use different grains between the two, and why you should use finer media in the optional last chamber.
Lastly, calcium reactors are complicated enough and although the most common way to manage the carbon dioxide injection is through the use of pH controller, we stick to more robust, old school techniques of balancing the CO2 and the feed rate. One of these techniques is a hybrid approach using an analog chemical pH indicator to determine the acidity at a glance and we’ve found it to be absurdly reliable and easy to use on the Aquavitro Element CA reactor which we don’t need to adjust very much.
The last tip we’d like to put out there is that we are often asked which method is ‘better’, direct dosing or calcium reactors, and there’s no simple answer to this question. It’s not an either/or situation because we use a single channel of buffer dosing on all our calcium reactor powered aquariums – we find it most practical to rely on the recirculating machine to handle 80% to 95% of the mineral demands and to use a separate dosing channel for fine adjustments of buffer to keep the alkalinity within the desired range.