FREE ISSN 1045-3520 Volume 19 Winter 2002 Introducing a Zonal Based Natural Photo by Robert Fenner Filtration System for Reef Aquariums by Steve Tyree Quite a few natural based filtration systems have been devised by reef aquarists and scientists in the past twenty years. Some systems utilized algae to remove organic and inorganic pollutants from the reef aquarium; others utilized sediment beds. The natural filtration system that I have been researching and designing is drastically different from both of these types. No external algae are used. I believe that all the algae a functional reef requires are already growing in the reef, even if they are not apparent. They include micro-algae, turf algae, coralline algae, single-cell algae within photosynthetic corals, and cyanobacteria with photosynthetic capabilities. Most of the systems that I have set up to research this concept have not included sediment beds. All organic matter and pollutants are recycled and processed within the system by macro-organisms. Sediment beds have not been utilized to process excess Miniata Grouper, Cephalopholis miniata organic debris, but that does not prevent other aquarists from adding them. The main concept behind my system is the use of living sponges, sea squirts, and filter feeders for filtration. Sponges consume bacteria, can reach about twenty inches in length in the wild, and dissolved and colloidal organic material, micro-plankton, The Coral Hind, Lapu about half that in captivity. It is undoubtedly the most and fine particulate matter. Sea squirts consume large Lapu, or Miniata prized member of the genus for the aquarium trade. It is bacteria, micro-plankton, and small particulate matter. beautiful, intelligent, and capable of gulping up small fish Filter feeders consume larger particulate matter. When Grouper, Cephalopholis and motile invertebrates. This species generally utilized with live rock and modern lighting, the aquarist tolerates shipping well, recovering at the retail shop well has a complete filtration system. miniata enough in a few days to go to the home aquarium. Any To set up this new system, the aquarist must by Robert Fenner torn fins that result from shipping will heal quickly. This establish separate zones having distinctly different fish is reclusive in nature, and will also be shy in a shop environmental parameters. Nutrient exchanges occur Cebu Island is a large island in the Philippines. We or home aquarium. between the zones. Before discussing these zones, we recently spent some time there with Dennis Mok and should discuss some details of basic nutrient cycling. Marty Beals, owners of Tideline in Los Angeles. We Environment and Behavior There has been much discussion about how much toured Lapu Lapu City and did some diving and A bigger aquarium is always better when food should be added to a reef tank of photosynthetic photography on Bohol Island, south of Cebu. We spent considering housing the true basses of the family corals. In the 1990’s, quite a few advanced reef aquarists one evening at a fresh seafood restaurant eating, among Serranidae, which includes the genus Cephalopholis. Even maintained heavily stocked small polyp stony (SPS) coral other delicacies, the Hind, a bass of the genus a small specimen should be in at least a sixty gallon tank, reefs. It was believed that adding large amounts of Cephalopholis, commonly known as the Miniata or even larger to encourage outgoing behavior. An external food was detrimental to the reef. Many of Grouper. This fish is also called the Lapu Lapu, as is the aquarium double this size is necessary for more than these reefs received only the minor amounts of food large town. This is the name of the local hero who one of the same or similar species. This species is added to supplement the diet of the herbivores. dispatched Ferdinand Magellan in 1521 and who has undemanding in regards to water chemistry, requiring Surprisingly, stony corals in some of these reefs grew at given his name to various other things. normal tropical sea temperature (low seventies to mid- phenomenal rates similar to natural growth rates. The Miniata, or Lapu Lapu, is a beautiful fish of eighties), specific gravity, and composition. Enhanced Recently it has become fashionable to add external typically shy bass-like behavior. It is tolerant of wide circulation, aeration, and filtration are beneficial in an food to a reef by target feeding the stony corals. The variations in water conditions, accepts most foods, and aquarium containing such voracious fish, as you can theory behind this is that the photosynthetic corals are is very resistant to disease. imagine. not able to supply from their symbiotic algae all the Range and Description As is typical of basses, this species does not like to nitrogen necessary for growth, although they do fulfill share its space with other fish. Yawning behavior and 100% of the daily respiration requirements. There is This grouper is common to many parts of the side-to-side alignment with tankmates are signs of speculation that corals that were not fed and still tropical Indo-Pacific, from the Red Sea to Durban, aggression that should not be ignored. Negative showed strong growth were consuming floating organic South Africa, and on most islands in the west-central interactions can be diminished be providing ample tank Pacific. It is not found in Hawaii or the Persian Gulf. It Continued on page 2 Continued on page 2 ©2002 Aquarium Systems, Inc., Mentor, OH - Printed in U.S.A. Introducing a Zonal Based Natural from the exposed zone where Filtration System for Reef Aquariums the excess particulate matter is produced. Large particulate Continued from page 1 matter is best processed by organisms in zones between material. A new study of the coral Pocillopora damicornis exposed and cryptic. I call on natural reefs supports this speculation. Briefly, the these semi-exposed and semi- study found that this coral was able to acquire nitrogen cryptic. These zones are by taking ammonium from sea water, enough to populated by non- support 100% of the growth demands of the coral and photosynthetic organisms that its symbiotic algae, even at normal ocean capture plankton and concentrations. Corals were also found capable of particulate matter, such as the supplying 11% of their nitrogen demands from feather duster worm, Bispira dissolved free amino acids. This indicates that aquarists viola. Animals in the cryptic do not need to feed SPS corals to insure adequate zone primarily consume nitrogen supplies. dissolved organic material, protozoans, and fine particulate matter. Water currents here should be very of this matter. In this zone there exists an excess slow. Cryptic sponges can become clogged if large amount of organic carbon compounds that are particulate matter is transported to their surfaces by strong currents. There are, however, many species of Photo by Tracy Gray consumed by the cryptic organisms in the dark zone. An aquarist must reevaluate the traditional reef sponge that thrive in more exposed zones and can be aquarium when he sets up this new zonal based system. placed in the semi-cryptic and semi-exposed zones. A traditional reef aquarium contains live rock and sand illuminated by very bright lights. Photosynthetic corals are placed on top of the live rocks and sand. Such a set up reproduces the upper region of a tropical reef that is exposed to light. It does not reproduce the complete Four corals grown from fragments in exposed zone. tropical reef platform. Researchers have found that at Photo by Tracy Gray least half the surfaces of a reef platform are not In my work with sponges and sea squirts I set up significantly exposed to light, but are cryptic in nature, some aquariums that received no added food at all. The and many surveys have found that these cryptic areas only added energy was in the form of light from metal can support just as much life as the exposed areas. halide lamps. These systems were divided into two sides, Aquarists should think of the typical exposed captive one light and one dark. An environmental gradient from reef as only a part of the whole zoned reef platform. strong light to almost no light was established. Although some aquarists have established caves in their Photosynthetic stony corals did very well here, as did reefs, such zones are small in size, and need to be coralline algae. Inorganic nitrate-nitrogen levels were expanded in scope. The exposed or illuminated part of slightly elevated, but well within the recommended a reef should be about equal in size to the cryptic zone. Cryptic zone organisms spreading on rocks. range. To my amazement, a large community of cryptic This would help to achieve a balance between the organisms was able to thrive in the dark area, including exposed zone where excess carbon based organic Our research has demonstrated that this Zonal numerous species of sponges and even a couple of sea compounds are generated, and the cryptic zone where Based Natural Filtration System works and is squirts. What was the food for these organisms? they are consumed, in part by bacterial and protozoan completely natural, with no risk of nitrate-nitrogen Because I used no sediment beds I was able to observe life forms. problems. Aquarists can establish habitats for organisms how much organic matter was created. The light side, The exposed zone can be set up the same way such as sponges and sea squirts that traditionally have termed the exposed zone, generated a large amount of current brightly lit reef tanks are set up now. The use of been viewed as difficult to maintain. The major particulate matter, primarily wastes from the herbivores to control algal growth will result in the drawback of this system is that it is difficult to acquire herbivorous fish, snails, and hermit crabs.