Calcium Supplementation Overview

Q. What does toxic ammonia convert into during the nitrogen cycle?

A. First, oxygen-loving bacteria, called Nitrosomonas, feed on ammonia and through biological processes they excrete nitrite, a less toxic but still dangerous chemical. Another oxygen-utilizing bacteria, called Nitrobacter, feeds on the nitrite, converting it into relatively harmless nitrate. Nitrate can be used by plants in the aquarium, or can be removed with water changes.

Many beginning hobbyists are anxious to add fish immediately after setting up a new aquarium. But the key to successful fish-keeping is patience and an understanding of what it takes to transform a container full of water into a life-supporting ecosystem free of toxic compounds.

Waste and Ammonia
Fish excrete waste and an unestablished (or uncycled) aquarium is not capable of processing these waste materials efficiently, so this creates toxic conditions for the fish. The result is fish loss. Your aquarium water must be free of toxic compounds in order for fish to survive and thrive.

Ammonia, perhaps the most notorious toxin, is introduced into your aquarium through fish waste, respiration, and other biological processes. It is extremely toxic and fish will show signs of stress, such as erratic swimming behavior, when ammonia is present. High levels of ammonia attack the gills first, causing fish to gasp at the surface. Continued exposure affects their fins and skin, and eventually their entire system is under attack.

In an established aquarium, ammonia is promptly converted into less toxic substances by beneficial bacteria through a natural process called the nitrogen cycle. New aquariums do not have established colonies of beneficial bacteria to adequately process these toxins.

What is Cycling?
So how does a new aquarium develop these bacterial colonies? Through a process called cycling. "Cycling" refers to the process of establishing and maturing biological filtration. Each new aquarium must go through cycling in order to establish efficient biological filtration capable of breaking down these toxic compounds. A food source for these bacteria, such as ammonia, is required to begin the cycling process. Certain beneficial bacteria use ammonia and oxygen to rapidly colonize aquarium and filter surfaces.

One way to establish beneficial bacteria is to set up the aquarium, fill it with dechlorinated water, turn on your pumps and filters, and add a small amount of fish food to the water. As the food breaks down, it supplies the food source bacteria need to multiply and colonize. This method can take several weeks.

Many aquarium keepers speed up the process by adding commercially-available cycling aids. Cycle and Stress Zyme are excellent products for this stage. Better yet, use a small amount of gravel from an established aquarium to cycle your new aquarium. This gravel already houses a good number of beneficial bacteria to speed up the cycling process.

Testing During Cycling
During cycling, test daily for ammonia and nitrite, the most toxic products in the nitrogen cycle. Most basic test kits include tests for ammonia and nitrite. When these two toxins are detectable by testing, you know that the bacterial population is not large enough to safely support fish and other inhabitants. But, as bacteria populations peak, both ammonia and nitrite levels begin to drop to the point where they are undetectable by testing.

Finally it is safe to begin stocking your aquarium. Add fish and aquatic life gradually since your system will once again need time to adjust to the increased ammonia generated by each fish. After cycling is complete, we recommend weekly testing of ammonia and nitrite to monitor water quality.

The amount of calcium provided through these means is sufficient for fish-only or lightly stocked reef aquariums where the biological demand for calcium is relatively low. However, in heavily stocked reef aquariums, calcium is utilized rapidly and supplementation is necessary to replenish these levels.

Calcium Supplementation & Alkalinity
Calcium supplementation poses a unique challenge due to a variety of chemical interactions that occur when introduced to saltwater. If calcium levels get too high (over 500ppm), there is a tendency for alkalinity to drop. This affects the buffering capacity of aquarium water and without adequate buffering, pH levels are susceptible to fluctuations. Conversely, if alkalinity gets too high, calcium levels tend to drop as calcium precipitates out of solution. A fine balance must be struck between the various aspects of saltwater to maintain ideal calcium levels.

Commercially available products help make calcium supplementation easier by taking out the guesswork. However, be sure to test and monitor calcium levels at least every two weeks, preferably once a week, to maintain the ideal calcium level at 350-450ppm. While testing calcium levels, remember to test and monitor alkalinity as well, since calcium and alkalinity levels influence one another.

The most common method of calcium supplementation involves the use of Kalkwasser preparations, balanced liquid calcium supplements or through the use of calcium reactors.

Kalkwasser
German for "lime water," Kalkwasser is simply calcium hydroxide dissolved in water to create a highly concentrated solution. It is used to both supplement calcium and to maintain high pH levels in reef aquariums of all sizes. It is extremely popular since it is readily available, inexpensive and easy to use. However, due to its very high pH (12.00+), the prepared kalkwasser solution must be introduced slowly through a dosing system to prevent drastic increases in pH. Dosing systems vary from electronic units to simple gravity fed units similar to drip IV units used in hospitals. Though the price of these units may vary, they utilize the same principle where the prepared kalkwasser solution is slowly dripped into the main aquarium or sump from a reservoir.

Balanced Liquid Calcium Supplements
Balanced Liquid Calcium supplements take convenience to the next level. These supplements safely increase calcium levels without affecting alkalinity and vice versa. Manufacturers have devised two-part formulations capable of maintaining both high calcium levels and alkalinity without causing negative reactions. If used per manufacturer's recommendations, there is little chance of overdosing or shocking the aquarium inhabitants. Liquid calcium supplements are extremely convenient and are ideal for smaller reef aquariums.

Calcium Reactors
Sophisticated devices such as calcium reactors help automate calcium supplementation in large or heavily stocked reef aquariums. These systems are generally comprised of a calcium reactor, circulation pump, CO2 delivery system, calcium media, and a pH controller. CO2 injected into the reactor chamber filled with the calcium media creates an acidic environment that slowly dissolves the media. The dissolved calcium is then mixed with saltwater and the resulting solution is slowly dripped into the main aquarium. Calcium reactors are very precise means of maintaining calcium levels within reef systems with high calcium demands.

There are many ways to supplement calcium depending on the size and stocking level of a particular reef system. Regardless of the method of supplementation, it is crucial to test calcium levels on a regular basis. Calcium supplementation is part of a dynamic and organic process in which calcium requirements increase as coral colonies (both soft and stony), coralline algae, and other organisms that actively use calcium grow. Regular testing and monitoring provide you with insight regarding the rate which corals are utilizing calcium and allow you to maintain the ideal levels for a healthy, beautiful coral garden.