Phillip Scheller on Deep Reefs
Aquarium of the Pacific's Phillip Scheller on Deep Reef Husbandry
Phillip Scheller is an aquarist at the Aquarium of the Pacific in Long Beach, California, and his success with deepwater, non-photosynthetic corals at the Aquarium was recently published in the May / June 2009 issue of CORAL Magazine. We wanted to follow-up with Scheller on his Deep Reef exhibit that was profiled in CORAL and see what else we could learn about successfully keeping these beautiful animals.
Our first question for Scheller was what he thought it was about the Deep Reef exhibit that so appeals to guests. “It’s the color,” says Scheller. “That’s what attracts guests to the tank, I think. A lot of people say it’s like autumn.” Autumn indeed. The low-light, 600-gallon aquarium is arresting in its intensity with bursts of orange, yellow, red, and purple. It’s like nothing that most aquarium guests have ever seen, and there is a good reason for that. Non-photosynthetic corals can be hard to keep—even for a public aquarium.
Scheller first attempted several non-photosynthetic corals from the genus Tubastraea in a smaller aquarium. These so-called sun corals did well, and he then began adding other non-photosynthetic corals to the display. “When I started with the non-photosynthetic corals,” he says, “I started by looking at those with big polyps.” Why? Scheller was thinking about food. Non-photosynthetic corals do not host symbiotic algae, and, as a result, they need to rely on food capture for their survival. Since little is known about the nutritional requirements of most non-photosynthetic corals, Scheller thought the non-photosynthetic corals with larger polyps were a logical starting point.
Today, a year and several months after first starting the 600-gallon tank that was profiled in CORAL, Scheller believes his approach to feeding the tank has been one of the hallmarks of the tank’s success. “Now we are using blended rotifers, which are about as small as you can get,” he says. In addition, he feeds the tank frozen CYCLOP-EEZE and frozen Mysis shrimp. Several times a week, live phytoplankton are added to the tank. Scheller uses the size and expansion of the polyps as his guide to how much and what type of food to feed.
“Since the publication of the CORAL article,” he says, “we’ve started adding spirulina to our daily feedings.” Spirulina is cyanobacteria (blue-green algae) from the genus Arthrospira (once classified as Spirulina spp., hence the name). It is commonly offered as part of a well-balanced diet for marine fishes, but Scheller has found that it seems to have a strong effect on the non-photosynthetic corals as well.
“The spirulina appears to initiate the expansion of the polyps a lot faster,” he says. As Scheller points out, we don’t really know very much about what these animals really eat. “Is it primarily phytoplankton or zooplankton?” he asks. “I think the spirulina simulates phytoplankton, and this is what stimulates the feeding response.” Regardless, Scheller, says, the addition of spirulina has yielded good results.
In addition to what Scheller is feeding the tank, when is also a critical consideration. “I feed every forty minutes,” Scheller says, although he acknowledges that part of the thinking behind such frequent feedings has to do with keeping the animals’ polyps open. He is, after all, caring for a display tank at a public aquarium. Obviously with all that feeding, there is a very real concern about the build-up of excessive nutrients in the tank. One thing that a public aquarium like the Aquarium of the Pacific has going for it is the fact that its massive seawater reservoir makes frequent, large water changes easy.
In the CORAL article, Scheller reports that he was performing twenty percent water changes daily in the tank, but he has recently backed off that a little. “We have cut down the number of water changes, and we have started doing smaller feedings,” he says. Scheller’s idea of cutting back on water changes is probably inconsistent with what most home aquarists think of when they think of doing less water changes. “Yeah,” Scheller says, “we are no longer doing daily water changes. We’ve cut down from seven days a week to about five.”
Does the home aquarist who wants to have success with these non-photosynthetic corals need to commit to a similar regiment of water changes? “No,” says Scheller. “To a certain extent, I feed as much as I do because I know I can get rid of the excess nutrients with frequent water changes, which are easily performed here.” Nonetheless Scheller recommends a beefy filtration system for the home aquarist interested in keeping non-photosynthetic corals. “Because most home aquarists can’t keep up with the frequency of water changes we perform here at the aquarium, they need to rely more heavily on filtration to remove excessive nutrients from the water.”
Scheller recommends a good protein skimmer, phosphate reactor and perhaps a denitrification system. “Basically it is normal reef set-up,” says Scheller, pointing out that stability in parameters is paramount. “I would also definitely say that having a filter bag is a must.” If there is a sandbed in the tank (and Scheller suggests only a very shallow one if you must have one), it should be vacuumed at least weekly. “Better yet,” Scheller continues, “go with a bare bottom tank and aim a powerhead at it so that any detritus and waste gets blown into suspension.” The exhibit at the Aquarium of the Pacific has a plenum under the sandbed. The sandbed itself ranges in depth from one to four inches, and he vacuums it weekly.
Feeding and nutrient export are undoubtedly two of the most important reasons Scheller’s tank has been so successful, but Scheller’s biggest concern without a doubt is flow. “Flow is absolutely critical to this system,” Scheller explains. The non-laminar, chaotic flow patterns in the tank allow for every polyp to capture food from every angle. “We use four powerheads in the display tank,” says Scheller. “There are even places where a powerhead is only one foot away from a coral—the coral is getting blasted with flow, and it still opens.” Each of these powerheads is rated to 900 gallons per hour, and there is a half-horsepower return pump.
While Scheller’s exhibit is meant to exemplify a deep reef and is therefore illuminated only dimly, he points out that non-photosynthetic corals can do well under brighter reef lighting. “Many of the species of non-photosynthetic corals that we have in the display also inhabit shallower water,” he says. Scheller does not believe that brighter reef-ready lighting will negatively impact most non-photosynthetic corals. “A bigger problem would be placing the coral in a shaded area of the aquarium where flow was decreased. Flow is a much more important consideration than light when it comes to the coral,” he says.
Scheller is not, however, as optimistic about deepwater species of fishes such as deepwater anthias and damselfishes. “The lower light levels are preferred by the fishes in the tank,” he points out, and while he isn’t prepared to say that exposure to bright, reef-ready light will negatively affect the health of a deepwater fish, he does prefer to keep deepwater species in tanks with lower levels of light.
In his CORAL Magazine article, Scheller goes on to discuss some of the invasive pests that can be a problem when keeping these animals in a set-up such as this, and the aquarist intent on moving forward with a non-photosynthetic coral-dominated reef tank should definitely get a copy. For those aquarists who live near Long Beach—or who may be visiting—definitely make sure to stop at the Aquarium of the Pacific and see Scheller’s deep reef display. There is nothing like over 100 large colonies of dendrophyllids (with at least eight species represented!) to inspire the reefer in you.