The Living Reef Aquarium
Currently, the most popular of the saltwater home aquaria is the living reef; complete with live rock, soft and hard corals, polyps, invertebrates, brittle stars, feather dusters, red and blue hermit crabs, and Astrea snails, while being virtually devoid of fish. Initially their popularity was economically limited as it was thought that to be successful, these aquaria had to be very large and equipped with elaborate filtration, lighting, and automated monitoring equipment. With increased species knowledge and more awareness of the biological functioning of a reef, this has proven to be false. Small, easy to maintain, affordable reef aquariums are available to anyone possessing basic water quality knowledge and an hour or so per week to devote to their maintenance. The rewards and enjoyment are unimaginable and ever-changing.
Due to the lighting requirements of many of the inhabitants, the aquarium should be of a longer, shallow construction, as opposed to the vertical "show" models available. Although equally functional, we would not recommend an aquarium of less than 20 gallon capacity. This restriction is primarily designed for visual pleasure, as the smaller aquariums do not provide sufficient area for species numbers and/or diversification.
Biological filtration is best provided by an Eco Plenum System (Reef Renovators). This is an adaptation of the Jaubert or Monaco style filtration system relying on natural bacteriological processes occurring within the aquarium. This system allows for excellent, virtually maintenance free biological filtration without the necessity or expense of overflow boxes, sumps, or water pumps. Approximately one pound of live rock per gallon of water is required. Many aquarists have reported better nitrite control and increased coral growth having used a seeding of live sand and live rock rather than live rock alone.
Mechanical filtration, strictly for debris removal and water clarity, should be provided by a simple, appropriately sized outside filter. It is not necessary to invest in the attributes of biological and chemical filtration capabilities as they are not necessary. The return flow from the filter will also serve to break surface tension, increasing oxygenation to the system.
Inexpensive illumination can be provided using either one or two twin tube fluorescent strip lights. One half of the bulbs should be of the actinic "blue" spectrum and the other half in the "white" full spectrum range. Timers should be used in conjunction with the lighting. A consistent and appropriate duration photo cycle is critical to proper coral growth and photosynthesis. If the lighting fixtures permit, the actinic bulbs should be the first on in the morning and the last off in the evening, allowing for a gradual conversion from daylight to darkness and vice versa. For rectangular aquariums with a frame of either 12 X 24 or 12 X 30, the Eclipse hood (Marineland) works excellently. It provides twin tube illumination and includes an integrated filtration system for debris removal.
Please be aware that fluorescent lighting probably will not provide sufficient illumination for all coral species and certainly not for the long term keeping of clams. The following can be used as a general guideline: When lighting the aquarium, bear in mind that corals can be loosely divided into two groups. Those within the color range of purple through red to orange and yellow do not require intense lighting. In contrast, those with beige, brown, green or blue coloring require strong lighting of the proper spectrum.
Circulating pumps or small powerheads are also necessary. Corals require a natural current to remove excreted organic waste matter and, conversely, to move nutrients within their reach. These pumps can be strategically located after the corals have been put in place, providing a more natural "wave-like" current.
A hang-on-the-back protein skimmer should be operating as soon as the live rock is introduced. Protein skimming is an area where the hobbyist can virtually spend as much as he/she wants without necessarily having increased the efficiency of the system. When making this decision, be aware that some skimming is better than none.
There are two distinct schools of thought regarding foam fractionization (protein skimming); both of which are equally well documented. One is that protein skimmers should be run twenty-four hours per day. The other being that protein skimming is indiscriminate in that which it removes and should therefore only be done eight to ten hours per day. This should probably be an area of personal preference decided by trial and error as which provides the best benefit for your reef aquarium.
Water quality is the absolute heart of the living reef aquarium. (See A Brief Introduction To The Saltwater Aquarium for more information on water and critical levels.) A living reef, by its very nature, is completely devoid of pollutants and excess nutrients. The same cannot be said for the tap water available to us. Success will largely be dependent upon using deionized or, at least, reverse osmosis water, and weekly testing of water quality parameters. The Aquatic Critter sells deionized, prebuffered, temperature controlled saltwater in five gallon containers.
Incidental equipment should include a high quality heater (preferably submersible), digital thermometer, saltwater test kits to include pH, ammonia, nitrite, nitrate and calcium, a hydrometer, pH buffer, calcium, a coral "conditioner" of choice and dechlorinator.
Recommended equipment would also include a titanium ground probe to remove induced voltage created by circulating pumps, heaters, power filters, and powerheads, and a copy of "Natural Reef Aquariums" by John Tullock. This is undoubtedly the most comprehensive, understandable text which has been published on the subject of maintaining a captive reef.