Introduction to Calcium & Alkalinity Maintenance

Michael Paletta - Guest Author
An Overview of Calcium & Alkalinity Maintenance: Part 1

One aspect of keeping reef aquariums that is starting to gain significant attention is the need to supplement calcium and the easiest means to do so. Until the late 1980's, water changes and the dissolution of calcium substrate were thought to keep calcium levels high enough. Consequently, a calcium supplementation regimen was not deemed necessary and additional supplementation was not readily practiced.

We now know that virtually all corals, as well as coralline algae, require constant supplementation of calcium in order to thrive. As coral colonies and coralline algae grow and spread, the demand for calcium increases as they utilize and deplete more and more calcium. Calcium supplementation helps meet these biological demands by replenishing calcium levels in a closed reef system.

The concept of supplementing calcium in the reef aquarium was first described in the late 1980's, when the Berlin System for keeping corals was introduced to the public. This was a significant moment since little attention was paid to the coral's need for calcium for them to thrive and grow, prior to this series of articles.

Initially, the only method described was the use of calcium hydroxide (Kalkwasser) dissolved in water to replace water that had evaporated. As reef aquariums became more sophisticated and stony corals and clams became the dominant features in these systems, more sophisticated methods of maintaining calcium levels have developed.

The methods that are currently being employed include: Kalkwasser, Kalkwasser and carbon dioxide, Calcium chloride and buffer, balanced liquid or dry supplements, a calcium reactor or a combination of these methods.

No single method is utilized exclusively since each method has its own particular shortcomings and is not universal or practical in all reef systems. However, it is still relatively easy to maintain the proper calcium level in most reef aquariums (just above 400 ppm, the level of natural seawater) as long as these factors are understood and managed.

We'll discuss the advantages as well as the shortcomings of these methods in a series of articles so you can determine which method is best suited for your particular situation. Remember, calcium demands will vary from aquarium to aquarium and a single approach may not be adequate. Consider tinkering with these methods to tailor an optimal supplementation method for your system.

Part 1 of 6. Continue reading:

Part 1
Intro

Part 2
Testing

Part 3
Kalkwasser

Part 4
Calcium Chloride

Part 5
Balanced Supplements

Part 6
Calcium Reactors

Products you may find helpful:
Dosers	Florida Crushed Coral	Calcium	Kalkwasser

Biography
Michael Paletta is the author of two books, "The New Marine Aquarium" and "Ultimate Marine Aquariums," and has acted as a consultant with the National Aquarium in Baltimore and the Pittsburgh Zoo Aquarium.