Become a Sponsor

Information Pages:
Marine Aquarium
Articles/ FAQs/Index
Freshwater Aquarium
Articles/ FAQs/Index
Planted Aquarium
Articles/ FAQs/Index
Brackish Systems
Articles/ FAQs/Index
Daily FAQs
FW Daily FAQs
SW Pix of the Day
FW Pix of the Day
Conscientious Aquarist Magazine
New On WWM
Helpful Links
Hobbyist Forum WetWebMedia Forum
Ask the WWM Crew a Question
Search Feature
Admin Index
Cover Images

The Ultimate Aquarium?
An Angelfish Communtiy Tank!

by Pete Giwojna

Travis Carter's all-time favorite fish are marine Angels.  Like so many of us, he is fascinated by the vivid hues, brilliant patterns, seemingly endless variety of color schemes, and feisty attitudes displayed by the Pomacentridae.  And rightly so.  Many people feel the Regal Angelfish (Pygoplites diacanthus) is the most beautiful fish in the ocean, with its alternating vertical bars of white, orange, and black, bright orange tail and chin, and brilliant blue highlights on its fins.  Others would accord that title to the Majestic Angelfish (Pomacanthus euxiphipops navarchus) or the Emperor Angel (Pomacanthus imperator).  It's hard to beat the elegant streamlined shape and electrifying colors of a well-marked Queen Angelfish (Holocanthus ciliaris).  Of course, the intensity of the neon blue markings on the Blue-Ring Angelfish (Pomacanthus annularis) and the Blue-Striped Angelfish (Chaetodontoplus septentrionalis) have made them the centerpiece of many a marine aquarium.  Certainly a dazzling dwarf angelfish (Centropyge spp.) is the star attraction of many smaller tanks.  And the rarity and bold markings of the Conspicuous Angelfish (Chaetodontoplus conspiculatus) make this exotic gem the crown jewel in many collections of reef fish.  Heck, that's one fish that many aquarists will actually design their entire aquarium system around.

The rarity and bold markings of the Conspicuous Angelfish (Chaetodontoplus conspiculatus) make this exotic gem the crown jewel in many collections of reef fish, and this community tank is no exception..  Even in a tank teeming with angelfish, tangs, and triggerfish, the Conspicuous Angel shown here is the undisputed ruler of the aquarium."  Photo by Joel Giwojna 

But Travis is not your average aquarist. 

He was not content to choose one, or two, or even a few of these Angelfish to grace his aquarium and do without the rest.  He wanted to add all of them to his collection.  And then some.  And he wanted to keep them all together in the same aquarium.  Peacefully and happily.  Along with assorted Triggerfish, various Tangs, and a bounty of Butterflyfish.  In short, his dream aquarium was an Angelfish community tank.

The problem with this plan is that marine Angels are solitary fish that are typically found either individually or as mated pairs of the wild.  In the aquarium, they are well-known for their territoriality.  As a rule, they will aggressively defend their turf against members of their own species, are apt to fight with other angelfish of the same genus, and often extend their hostility towards any other similar-looking fish of roughly the same size (Fenner 2004).  Consequently, most experts recommend keeping just one angelfish from any given genus per aquarium.  And the best advice is often to limit yourself to one Angelfish of any kind, which will inevitably emerge as the top dog of the aquarium and rule the roost with little need to assert its dominance thereafter (Fenner 2004).   

A community aquarium composed primarily of Angelfish would therefore seem to be out of the question.  And sure enough, Travis' initial attempts to establish an Angelfish community in a traditional aquarium system eventually failed due to outbreaks of disease.  No doubt most aquarists would have abandoned their overambitious Angelfish project after a few such setbacks. 

But Travis is not your ordinary home hobbyist.  His passion and zeal for Angelfish know no bounds, and he was willing to do whatever it takes to make his impossible dream a reality.  When it became obvious that a conventional approach would not produce the desired results, he was more than willing to try some unconventional alternatives.  With some expert advice from Joel at Aquatic Environments, a new aquarium system was designed that would "push the envelope" in a number of ways.  If that meant they would be exploring uncharted territory, blazing new trails, and boldly venturing where few aquarists had ever gone before, so much the better.  And so Travis launched himself into a new Angelfish adventure with renewed energy and his usual unbridled enthusiasm.

The first step was to set up a large aquarium with lots of elbow room, provide an abundance of shelter and hiding pieces, beef up the filtration system, and institute strict disease prevention measures.  A 250-gallon aquarium was established to serve as the Angelfish community tank and gradually stocked with fish handpicked by Travis himself over a period of weeks and months.   

Live rock arranged to create a labyrinth of caves, arches, and overhanging shelves and ledges provides natural surroundings and abundant cover for all the inhabitants of the 250-gallon community tank.  Photo by Travis Carter

It is now eight months later and the results thus far have been nothing short of spectacular!  The community tank currently houses no less than 26 different Angelfish along with dozens of Tangs, assorted Butterflyfish, and seven Triggerfish, among others.  Included among the Angelfish are nine Pomacanthus species, three Holocanthus angelfish, and six Centropyge species as well as a number of exotic Angels from other genera.  As you can imagine, the aquarium is absolutely ablaze with color and activity.  It resembles nothing more than a bustling coral reef scene from a nature documentary, only the swarms of exotic fish are Angelfish and Tangs and Butterflies, not Damselfish and Anthias, and it's all taking place in the executive office of US Internet in Minneapolis rather than a pristine Polynesian reef in the middle of the ocean!  Contrary to what you might expect, there is very little aggression and almost no overt hostility (for reasons we'll discuss in more detail later).  The fish are all coexisting peacefully, they have retained their brilliant coloration, and they are always out in the open, actively exploring their surroundings and boldly displaying themselves.  And they are thriving on a staple diet of assorted pellet foods. They are fat and healthy and many of them have grown considerably since they were first introduced to the aquarium.

Here is a complete list of the aquarium residents:

Large Angels:
1 x 6-7” Conspicuous Angel (Chaetodontoplus conspiculatus)
1 x 5-6" Griffis' Angelfish (Apolemichthys griffisi)
1 x 4-5” Personifer or Queensland Yellowtail Angelfish (Chaetodontoplus personifer)
1 x 2-3” Red Sea Regal Angel (Pygoplites diacanthus)
1 x 4-5" Blue-Striped Angelfish (Chaetodontoplus septentrionalis)
2 x 4-5” Pair of Scribbled Angels (Chaetodontoplus duboulayi)
1 x 3-4” Emperor Angelfish juvenile (Pomacanthus imperator)
1 x 3-4” Majestic or Blue-Girdled Angelfish (Pomacanthus euxiphipops navarchus)
1 x 3-4” Blueface Angel (Pomacanthus euxiphipops xanthometopon)
1 x 4-5” Blue-Ringed Angel (Pomacanthus annularis)
1 x 2-3” Koran Angel juvenile (Pomacanthus semicirculatus)
1 x 2-3” Rock Beauty Angel (Holocanthus tricolor)
1 x 4-5” French Angel (Pomacanthus paru)
1 x 2-3” Queen Angel (Holocanthus ciliaris)
1 x 4-5” Asfur Angel (Pomacanthus asfur)
1 x 2-3” Yellow-Band Angel (Pomacanthus maculosus)
1 x 3-4” Chrysurus or Gold Tail Angel (Pomacanthus chrysurus)
1 x 1-2” King Angel (Holacanthus passer)
1 x 4-5” Flagfin Angel (Apolemichthys trimaculatus)

Dwarf Angels:
1 x 3-4" Japanese Pigmy Angelfish (Centropyge interruptus)
1 x 2-3” Orange Lemonpeel Angel (Centropyge flavissimus)
1 x 1-2” Goldflake Angel (Apolemichthys xanthopuntatus)
1 x 3-4" Bicolor or Oriole Angelfish (Centropyge bicolor)
1 x 2-3” Flame Angel (Centropyge loriculus)
1 x 2-3” Coral Beauty Angel (Centropyge bispinosus)

1 x 2-3" Indian Headband Butterfly (Chaetodon mitratus)
1 x 2-3" Declevis or Marquesan Butterflyfish (Chaetodon declevis)
4 x 3-5" Red Sea Golden Butterflies (Chaetodon semilarvatus)

3 x 2-3” Purple Tangs (Zebrasoma xanthurum)
1 x 2-3” Power Blue Tang (Acanthurus lucosternon)
1 x 3-4” Blonde Naso Tang (Naso lituratus)
5 x 1-3” Blue Tangs (Paracanthurus hepatus)
1 x 3-4” Chevron Tang (Ctenochaetus hawaiiensis)
4 x 2-3” Yellow Tangs (Zebrasoma flaviscens)

1 x 4-5” Clown Trigger (Balistoides conspicillum)
1 x 5-6” female Crosshatch Triggerfish (Xanthichthys mento)
2 x 2-3” Blue Throat Triggers (Xanthichthys auromarginatus) -- a M/F pair
1 x 2-3" Humu Humu or Picasso Triggerfish (Rhinecanthus aculeatus)
2 x 3-4” Niger Triggers (Odonus niger)

1 x 2-3” Polleni or Harlequin Grouper (Cepholopholis polleni)
1 x 1-2” Flame Hawk Fish (Neocirrhites armatus)
1 x 1-2” Black box fish (Ostacion meleagris)
6 x 2-3” Dragon Gobies (Gobioides broussonetti)
3 x 3-4” Engineer Gobies (Pholidichthys leucotaenia)

That makes a grand total of 66 reef fish in this spectacular community tank, many of which are rare, highly prized specimens that are difficult to obtain.  Yup, you're correct -- that is indeed an incredible amount of marine fish to keep in any conventional marine aquarium.  But Travis is not a conventional aquarist and this is not a traditional aquarium.  In this article, we will discuss the factors that make this unorthodox community tank so successful, and as you will see, there is method to his madness. 

Nothing goes to waste in this tank full of voracious eaters, and the fish will continue to glean the bottom until nothing edible is left.  Photo by Joel Giwojna

The spectacular fish are the decorations in this aquarium so they rockwork aquascaping is very simple yet extremely effective.  Photo by Travis Carter

It might surprise you to learn that the cornerstones of this unusual aquarium system are the same basic principles of good aquarium management that all hobbyist should follow.  Like an entire generation of hobbyists, Travis was first inspired to become a fish-keeper after reading Bob Fenner's landmark book, The Conscientious Marine Aquarist.  As a Fenner disciple, he is well-versed in the fundamentals of aquarium keeping.  The success of this Angelfish community tank depends not upon gimmicks but rather on religiously adhering to the principles of sound aquarium management and carrying them out to the Nth degree.  This includes: 

  1. maintaining optimal water quality at all times

  2. providing a highly nutritious, varied diet that features numerous small feedings spread throughout the day

  3. furnishing a stress-free environment with natural surroundings that provide abundant shelter and cover for all of the fish

  4. practicing aggressive disease prevention measures

  5. relocating large specimens to more spacious accommodations as they grow. 

Let's take a closer look each of these aspects of sound aquarium management as they apply to this awesome Angelfish community tank in greater detail.

 Water Quality 

First and foremost, the filtration system for the angelfish community tank is designed to provide optimum water quality.  If you're unable to maintain good water quality in a heavily loaded aquarium, nothing else that you do will matter.  With that in mind, a 250-gallon aquarium equipped with an equally large sump was installed in order to provide stable conditions for the community tank. By equally large, I mean that Aquatic Environments in Minneapolis designed and installed a Maxi-Sump specifically for this aquarium that takes advantage of every inch of space under the tank in order to provide a sump/refugium of maximum possible size.  The new sump was custom-made to fit the exact dimensions of the aquarium stand and then slid into place from above before the aquarium itself was installed.   

The bulk of the nitrification and denitrification for the aquarium are provided by over 300 pounds of live rock.  An oversized custom-made wet/dry trickle filter supplies supplemental biological filtration to assure that the ammonia and nitrate levels remain at zero at all times.  Anaerobic denitrifying bacteria in the interior of the porous live rock keep the nitrate levels low by converting the nitrates to harmless nitrogen gas almost as fast as they are formed.

 The Angelfish, Tangs, Butterflies, and Triggerfish in the community aquarium are all active fish that require high oxygen levels in order to thrive (Fenner 2004).  Efficient oxygenation begins with the wet/dry filter that features a thin film of water slowly trickling over filter media with an ultra-large surface area, thereby allowing maximum air-water contact. This provides excellent oxygenation with efficient offgassing, which helps keep dissolved oxygen levels high and carbon dioxide levels low at all times.  An efficient external protein skimmer equipped with ozone further improves the water quality and aeration of the aquarium.  ORP controllers regulate the introduction of ozone into the bubble column of the skimmer, continuously adjusting the oxidation-reduction potential of the aquarium. 

A minimum of 100 gallons of saltwater are replaced weekly without fail.  The newly mixed saltwater is made from RO/DI water and is preadjusted to the same temperature, pH, and salinity as the main tank before the water changes are performed.  This assures that at least 40% of the aquarium water is replaced every week.  The aquarium is equipped with an Aqua Controller which provides continuous measurements of the pH, ammonia, nitrites, water temperature and specific gravity on a real-time basis, and additional water changes are performed whenever the trends indicated by these readings suggests that it would be beneficial.  This exemplary maintenance protocol thus assures that the water quality in the angelfish community tank remains rock solid despite the heavy bioload.

Although this is a fish-only system, the water chemistry in the community tank is monitored and regulated as though it were a reef system to assure that nothing is overlooked.  Aside from the basic water quality parameters, the carbonate hardness, total alkalinity, and calcium and phosphorus levels in the aquarium are checked several times a week, which is an important precaution for marine aquarium that maintains a salinity of only 15 parts per thousand.  The aquarium is dosed with calcium, magnesium and iodine regularly to maintain optimum levels at all times. 

Bottom Feeders: hungry fish scour the bottom for leftover food granules and pellets.  Included here are a scribbled angel, clown triggerfish, blue-striped angelfish, and a blue-ring angel among others.  Photo by Joel Giwojna


A highly nutritious diet is equally important.  Pristine water quality won't keep the community tank healthy if the fish are malnourished or develop dietary deficiencies.  This is especially crucial for Marine Angelfish (Pomacanthidae) and Tangs which are prone to characteristic disease problems if their diet is deficient in key nutrients and vitamins.  The most serious of these are head and lateral line erosion (HLLE) and vitamin A blindness (Fenner 2004).  Head and lateral line erosion is associated with a deficiency of one or more of the following nutrients: Vitamin C, Vitamin D, calcium, or phosphorus.  It can effectively be prevented by feeding Angelfish and Tangs foods high in vegetable fiber and rich in calcium and vitamins C and D.  Similarly, blindness in Marine Angelfish can result from a deficiency of Vitamin A (Fenner 2004).  It is now known that Vitamin A blindness is problematic in angels that do not receive enough green material in their diets.

Angelfish are particularly prone to such dietary deficiencies because of their specialized feeding habits in the wild.  Many angelfish feed primarily on sponges and tunicates in the ocean (Marine Angelfish 2007).  Angels from the genus Holocanthus and the genus Pomacanthus, in particular are habitual sponge grazers in their natural habitat, and it's imperative for their color and general health to include some sponge-containing material in their diet (Fenner et al., 2004). Co-enzymes derived from the poriferans in the diets of these Angelfish are largely responsible for their brilliant, intense coloration.  Consequently, in order for angelfish to retain their vivid colors and look their best and brightest, their diet should include plenty of natural color enhancers such as carotenes and xanthophylls.  Marine organisms cannot synthesize these pigments, so if they do not receive adequate amounts in their diet in a form that's easy for them to absorb, their colors will fade over time. 

Likewise, in order to sustain proper growth and development, juvenile Marine Angelfish require a diet rich in highly unsaturated fatty acids (HUFA), including the DHA omega 6 and omega 3 series, which are extra long chain fatty acids that are absent in virtually all live and frozen feeds (Giwojna, 2002). Most marine organisms, angelfish included, cannot synthesize these long chain fatty acids and must obtain them through their diet.  DHA, for instance, has been proven to be essential to high survivability, nerve development, stress management, and proper reproduction in fishes (Giwojna, 2002). 

Finally, Marine Angelfish are omnivorous, so it's important to provide them with a varied diet that includes plenty of vegetable matter as well as proteins and lipids.  For best results, experts suggest that fully half of the diet of Marine Angelfish should consist of plant material (Campbell in Fenner 2004).  Moreover, the vegetable matter and proteins and lipids in their diet need to be of marine origin so that it can be readily digested and absorbed.  (Laterally compressed fish such as angelfish, butterflies, and tangs are more prone to constipation, and providing a varied diet rich in vegetable material is the best way to prevent such problems.) 

Providing a suitable diet that meets all of the above requirements was especially challenging for Travis' Angelfish community tank because it is an office aquarium.  Nobody is there to feed the fish on the weekends or holidays, so the foods that are provided must be suitable for use in an automatic fish feeder. 

The diet developed by the experts at Aquatic Environments to meet these demanding feeding requirements is based primarily on a variety of pellet foods and granulated foods, including products designed for use in commercial aquaculture as well as for the ornamental fish industry.  A mixture of granulated foods from several different sources that have been derived from natural marine products and fortified with the proper vitamins and minerals serves as the staple diet for the angelfish community tank.  This is complemented by daily feedings of vegetable material of marine origin (Nori, kelp-based sheet algae, and macroalgae) in quantities that amount to roughly 50% of the fishes' diet. 

The following combination of granulated foods was devised to meet the strict needs and requirements of the angelfish: 

  • Nelson's Silver Cup Tropical Breeder Feed "Scientific Fry" No.2 (sinking -- 0.84-1.38 mm) for protein + vitamins A, D, and E.

  • Ziegler's Salmon Starter for rapid growth plus additional enrichment and variety.

  • Ocean Nutrition Formula Two Marine Pellets (small) for its high vegetable content and stabilized Vitamin C.

  • Ocean Nutrition Formula One Marine Pellets (small) for HUFA, enhanced disease resistance and additional Vitamin C.

  • Boyd's Vita Diet Marine (slow sinking pellets -- 1.5 mm) for supplemental vitamins and additional color enhancers.

To assure that all of fish get enough to eat every day, eight feedings of these pellet foods are offered throughout the day, rather than one or two large feedings.  The granulated foods are dispensed by a sophisticated automatic feeder that includes a fan and a heating element to control humidity and keep the pellets dry, which effectively prevents clumping, while a photoelectric eye prevents the pellets from being dispensed after the aquarium lights have been turned off.  Along with the right combination of pellet foods, the proper proportion of large granules to small food granules is also carefully calculated for every feeding.  The bigger fish naturally concentrate on the largest food granules, allowing the smaller fish to go after the smallest pellets. 

As shown here, the moment the first pellets hit the water, the entire aquarium explodes in a flurry of activity and erupts in a riot of colors as gaudy fish rush in from every corner of the tank and converge at the source of the bonanza. Note: the dark specks and bright flecks shown in the water column and along the flanks of the fish are actually the pellets and granulated foods drifting slowly to the bottom.  Photo by Joel Giwojna

Roughly 50% of the fish's diet consists of vegetable matter, so as you can imagine, there is a lot of competition for algae which gets chomped down amazingly fast.  Photo by Joel Giwojna

In addition to the eight portions of pellet food granules, algae clips are kept loaded with macroalgae and sheet algae to assure that the fish have something to graze on throughout the day.  Nori and different types of sheet algae are alternated with occasional feedings of live macroalgae.

To further enhance this "meat and potatoes" staple diet of pellet foods and vegetable matter, the menu of the fish is supplemented liberally with enriched frozen Mysis, sponge-containing products, and specialty foods for angelfish.  These frozen food supplements include the sponge-based Angel Formula by Ocean Nutrition as well as their Pigmy Angel Formula, which is designed especially for Centropyge angelfish.  The frozen Mysis is enriched with Vibrance One, which includes a potent immunostimulant (beta-glucan), pure Astaxanthin and other color-enhancing carotenoids, water-soluble vitamin C, and various other essential vitamins and minerals in the proper proportions.  Regular feedings of the fortified Mysis, sponge material, and Angelfish formulas are offered during the working week.

All things considered, this feeding regimen has proven to be very successful.  It has good variety, a high content of vegetable fiber in easily digestible form, and is designed specifically to meet the unique dietary requirements of angelfish.  It's highly nutritious, rich in protein and highly unsaturated fatty acids to promote good growth, and fortified with the vitamins and minerals necessary to prevent head and lateral line erosion and vitamin A blindness.  Best of all, the fish eat the various foods that comprise their diet with great gusto.  They attack them aggressively and devour their specially prepared foods greedily.

Even the pellet foods, which comprise the bulk of their daily diet, are eagerly eaten.  This is surprising because several of the fish in the community are considered notoriously finicky eaters that are difficult to feed in captivity, and which typically ignore granulated foods and other prepared food products.  That's not the case in this aquarium.  All of the fish in the angel community tank devour food pellets like there was no tomorrow.

Several possible reasons for this come to mind.  For one thing, all of the granulated foods are derived from natural marine products.  So although they may be in unnatural form, they smell good and taste good; once the fish have sampled them, they immediately recognize the familiar tastes and the food pellets are eagerly accepted thereafter.  The trick is just to get the newcomers to take that first bite of the pellets.  And that's where the other factors come into play.

For instance, many of the fish are juveniles and young specimens that are more adaptable in their feeding habits and can adjust to strange foods readily.  Unlike adult specimens, the youngsters are not hardwired for a specialized diet with their food preferences set in stone.  And no doubt the extremely competitive atmosphere in the aquarium also has a lot to do with the willingness to dive in and join the rest of the crowd at feeding time.  The fish do not fight over the food, but as you can imagine, there is a great deal of competition at mealtime in the "first come, first served" sense of the word.  When newcomers see all of the other fish going nuts over the pellet foods, they quickly get the idea that it's good to eat and don't want to miss out on their share of the goodies.  In this dynamic community tank, nobody wants to be late for dinner! 

I believe that classic Pavlovian conditioning also plays a strong role in the fishes' aggressive feeding response.  When the automatic fish feeder clicks on eight times a day and dispenses the delicious pellets like manna from Heaven, it doesn't take long for the fish to associate the "click" of the feeder with good things to eat.  That association is positively reinforced eight times a day, so even new additions are soon responding to the stimulus of the automatic feeder switching into motion like the ringing of a dinner bell. 

Only in this aquarium will you see a dainty Lemonpeel dwarf angel brazenly brushing aside a much larger Conspicuous Angel and clown triggerfish for its share of the sheet algae.  Photo by Joel Giwojna

Whatever the reason or reasons, it's an undeniable fact that all of the residents of the aquarium are aggressive eaters that go crazy for pellet foods and sheet algae.  And that makes feeding time in the Angelfish community tank a sight to behold! 

We have all marveled at the film footage of a school of piranha making the water boil as they relentlessly stripped the flesh from an animal carcass and skeletonized it in a matter of minutes, or watched with bated breath while a diver recorded a feeding frenzy of sharks from a fish's eye view, and certainly those are compelling scenes that excite the imagination.  But I'm here to tell you that that you haven't seen anything yet until you have experience the thrill of witnessing an angelfish feeding frenzy erupt before your very eyes.  About once every hour, Travis' automatic fish feeder clicks into action and dumps a carefully prepared combination of gourmet goodies into his community tank.  The moment the first pellets hit the water, the entire aquarium explodes in a flurry of activity and erupts in a riot of colors as gaudy fish rush in from every corner of the tank and converge at the source of the bonanza.  At first glance, it's like looking through the rotating barrel of a kaleidoscope as shimmering shards of brilliant color swirl about in ever shifting patterns, come together briefly to form a mosaic of glittering colors, and then break apart momentarily only to coalesce once again in different combinations that are even more dazzling.  The eye struggles to take it all in and make sense of the whirlpool of darting movements and fleeting flashes of color, and it takes a moment to adjust to the sensory overload before you can quite comprehend exactly what you are seeing. 

But once the adjustment has been made and your eyes catch up with the frantic pace, so that you can finally focus on individual fish, some astounding sights begin to emerge from the chaotic clash of colors.  A dainty Dwarf Angelfish (Centropyge loriculus) jockeying for position with a spectacular Conspicuous Angel (Chaetodontoplus conspiculatus) many times its size and challenging it for a choice morsel.  A Red Sea Regal Angelfish (Pygoplites diacanthus) right in the thick of the melee, greedily gobbling up pellets one after the other as fast as possible.  (Who said regals were finicky eaters?)  A delicate Butterfly fish (Chaetodon mitratus) swooping in to snatch a tasty tidbit away from the much larger but less maneuverable clown triggerfish.  A squadron of Golden Butterflies strafing the bottom for pellets that have settled to the substrate while formations of purple tangs and blue tangs patrol in midwater, snatching up drifting pellets from the water column as dozens of assorted Angelfish swarm over their heads.  Glorious!

 Aquarium Décor 

The spectacular fish are the decorations in this aquarium so the aquascaping is very simple yet extremely effective.  It consists of well over 300 pounds of live rock arranged in a labyrinth of caves, arches, and overhanging shelves and ledges to maximize the amount of shelter and protection it offers.  Each individual piece of the live rock was handpicked for the many holes, cavities, gouges and grooves that riddle its surface in order to provide additional microhabitats for the smaller fish.   

The result is a reef face biotype that provides the marine tropicals with familiar surroundings and an abundance of cover.  No matter where they go in the aquarium, a convenient hidey hole or sheltered nook is never more than a foot away from the fish at any time.  This seems to give them a great sense of security and the fish are very much at home amid these natural surroundings.  Perhaps because there is always a handy hiding place or safe haven within easy reach, the fish are not at all inclined to hide.  They are relaxed, weaving lazily in an out of the rockwork and leisurely exploring their surroundings.  They put themselves on parade and boldly patrol the open water. 

Aside from pellet food, one can also trigger a feeding frenzy in this tank full of algae eaters by introducing sheet algae or macroalgae for the fish to graze on throughout the day.  In this photo, a generous portion of sheet algae has been just added to tank and all the fish are coming out of the rockwork to swarm the white lettuce clip adhering to the front glass.  This photo also shows the rockwork structure that provides plenty of cover to make the fish feel comfortable and secure.  Photo by Joel Giwojna

Remarkably, this applies to the new additions as well.  Rather than concealing themselves, cringing in the background, and desperately trying to remain inconspicuous or out of sight, as you might expect of newcomers that have just been introduced into a strange new environment teeming with Angels, Triggers and Tangs, they remain in the open and school freely among themselves and the established residents of the aquarium.  Very often, they are grazing nonchalantly on the live rock moments after being released in the aquarium.  And as likely as not, when the first serving of pellet foods is dispensed, the new arrivals will dive in and partake with the others. 

I suspect that the ease with which the new additions adjust to the community tank is largely because they are taking their cues from the established fish.  The longtime residents are relaxed, swimming about unconcerned and just generally ignoring the newcomers, giving them the impression it's completely safe to remain out in the open as well.  In essence, the very well stocked community tank is like an entire aquarium of dither fish, coaxing the new fish into the thick of the action.  Fascinating!

 Disease Prevention and Control

 When it comes to disease, prevention is always the best cure, and nowhere is this more true than in a community tank heavily stocked with rare, highly prized fish.  Aquatic Environments and Travis have accordingly instituted strict disease prevention protocols for this unique Angelfish aquarium system, including the following prophylactic measures: 

  • Hyposalinity

  • Ozonation

  • Ultraviolet sterilization

  • Immunostimulants

Let's examine each of these disease prevention measures individually a little more closely: 


Hyposalinity, or osmotic shock therapy is at once perhaps the most controversial and the most effective of the disease prevention measures used to protect the angelfish aquarium from disease.  As the name suggests, this method of disease prevention simply involves maintaining the aquarium at a lower salinity than normal -- in this case, 15 ppt (specific gravity = 1.011-1.012).  (To assure accuracy, a refractometer is used to measure and regulate the salinity.)   

Hyposalinity is an effective technique because Marine Ich (Cryptocaryon irritans), external trematodes, and most ectoparasites and protozoal parasites cannot survive for long at such low salinity.  And since most of the bacterial and fungal problems that plague marine fish are secondary infections that take hold after the fish's integument has been compromised by a mechanical injury or external parasites, eliminating those ectoparasites via hyposalinity also helps minimize problems with bacteria and fungus.  In addition, hyposalinity helps parasite-ridden fish avoid dehydration and save their strength by reducing osmotic pressure and making it easier for them to osmoregulate. Allow me to elaborate.  

Because the seawater they live in is far saltier than their blood and internal body fluids (Kollman, 1998), marine fish are constantly losing water by diffusion through their gills and the surface of their skin, as well as in their urine (Kollman, 1998). The mucus layer or slime coat of the fish helps waterproof the skin and reduces the amount of water that can diffuse through its surface (Kollman, 1998). However, when the skin is compromised by abrasions or attacked by parasites such as Costia, Cryptocaryon, Cryptobia, Amyloodinium, Brooklynella, Epistylus and the like, this protective barrier is damaged and water is lost at an increasing rate (Kollman, 1998). The affected fish can easily become dehydrated as a result, further debilitating them.  

Low salinity is an excellent way to treat most such skin infections, since reducing the salinity helps the fish recover in several different ways (Lowry 2004). It lessens the risk of dehydration by decreasing osmotic pressure (Kollman, 1998), and reduces the amount of energy the fish must expend on osmoregulation, helping the weakened fish to recover (Kollman, 1998).  

And if the salinity is dropped far enough, as in this case, it prevents reinfection and provides the fish with immediate relief by destroying the parasites in the water and on the surface of the skin (Kollman, 1998). At low salinity, water moves into the parasites' bodies by passive diffusion until they literally burst (lyse). This method of treatment is known as hyposalinity or Osmotic Shock Therapy.  

In the eight months sense the salinity of the Angelfish community tank was adjusted to 15 ppt, there have been no ectoparasite problems of any kind.  Period.  This includes the outbreaks of Cryptocaryon and Oodinium that eventually doomed Travis' early attempts to establish such an Angelfish aquarium. 

A Declevis butterflyfish and a beautiful blue-striped angelfish duel for a delectable morsel under the watchful eye of a powder blue tang."  Photo by Joel Giwojnayposalinity is a well-established disease control procedure and its hard to argue with those results, but it's a controversial approach in this instance because of the duration that the hyposalinity has been maintained.  The hyposalinity was initially instituted during the high-risk period when the community tank was being gradually stocked and groups of new fish were being introduced into the aquarium every week or two.  It is very common for new arrivals to carry Cryptocaryon or Amyloodinium or other parasites into the main tank, and maintaining the salinity at levels appropriate for osmotic shock therapy can minimize such problems while a new aquarium is being populated.  In this case, however, stocking the aquarium has lasted fully eight months, and the fish have been doing so beautifully that Travis plans to maintain the hyposalinity indefinitely.  To the best of my knowledge, that's something that has never been attempted before with an aquarium of this nature. 

Osmotic shock therapy is normally administered only as a short-term bath, while hyposalinity is traditionally administered in a hospital tank while fishes are being quarantined.  Under such circumstances, the hyposalinity may be maintained as long as 30-45 days (Lowry 2004), in order to assure that the entire life cycle of any parasites has been thoroughly accounted for and neutralized.  Wholesalers and retail pet dealers often maintain hyposalinity in their crowded holding tanks at all times, but there is such a rapid turnover of fish at such establishments that no specimens remain in the systems for any length of time.  So there is very little data available regarding the long-term effects of hyposalinity on marine fish. 

Although it's an established fact that hyposalinity or osmotic shock therapy can protect marine fish from Cryptocaryon, external trematodes, gill flukes and most protozoal infections, it is by no means a cure all.  It has no effect on internal parasites or primary bacterial, viral, or fungal infections (Lowry 2004).  Other disease prevention measures are necessary to protect the Angelfish community tank from such health problems.   

Accordingly, metronidazole and praziquantel are kept on hand to be administered orally should problems with internal parasites ever be indicated, and ozonation and ultraviolet sterilization are employed on the aquarium to keep microbes at low levels. 


Ozone (O3) is the highly unstable triatomic form of oxygen.  The instability of the ozone molecule makes it highly reactive, and it oxidizes or "burns up" organic compounds and microbes on contact.  As a result, ozone is widely used for water purification and sterilization, particularly in Europe (Fenner, 2003).  When used in conjunction with a protein skimmer and properly administered, it provides many benefits for the aquarium as well. 

Ozone chemically degrades large organic molecules, thereby helping to raise pH, increase dissolved oxygen levels and Redox potential, and improve water quality in general while enhancing the efficiency of your protein skimmer (Fenner, 2003).  Its ability to destroy microbes on contact also makes it a very useful disease control measure.  Virtually all the large public aquaria employ ozone in their systems for these reasons. 

In Travis' Angelfish community tank, the ozone is regulated by an ORP controller and introduced into the bubble stream of an AquaMedic external protein skimmer.  When the ORP reading drops, indicating that more ozone is needed to reach the desired setpoint, the ozonizer can put out up to 200 mg of O3 per hour, which is more than adequate for this particular aquarium.  I should also point out that the discharge from the protein skimmers is very well filtered through activated carbon before it enters the sump or the atmosphere.  A pair of ultraviolet sterilizers then picks up where the ozone leaves off for additional protection.

Ultraviolet Sterilizers 

Although it does not improve water quality to nearly the same degree as an ozonizer used in conjunction with a protein skimmer, UV radiation in the proper range (295-400 nanometers) is known to help oxidize phosphates, metabolites, organic molecules and nitrogenous compounds through the incidental production of ozone (Fenner, 2003).  

The primary benefits UV sterilization provides, however, are disease reduction and the control of nuisance algae. Ultraviolet radiation can be very effective in reducing free-floating algae, bacteria and microbes in general, certain parasites while in the free-swimming stages of development, and other suspended microscopic organisms (Fenner, 2003).  A properly installed and maintained UV sterilizer can be invaluable in reducing the incidence and spread of such infections in heavily stocked aquaria.  The Angelfish community tank is thus equipped with two separate 36-Watt Turbo Twist ultraviolet sterilizers.  Aquatic Environments assures that the quartz sleeves are cleaned regularly, the UV bulbs are replaced on schedule, and the units are operating at peak efficiency.  When properly used in this manner, UV sterilization can reduce microbial levels in the aquarium to the low levels normally found in the wild or below (Fenner, 2003).  

Boosting the Immune System 

To further improve their disease resistance, all of the fish in the community tank receive daily doses of various natural immunostimulants as part of their everyday diet.  Chief among these is beta glucan, which is a primary ingredient in the Ocean Rider Vibrance, (the powdered enrichment formula used to fortify the frozen Mysis).  Administering beta glucan orally stimulates phagocytosis of certain white cells (macrophages).  Studies show that beta glucan can thus help prevent infections from bacteria, fungus, and viral elements. 

Research also indicates beta glucan helps prevent infections and helps wounds heal more quickly (Bartelme, 2001). It is safe to use in conjunction with other treatments and has been proven to increase the effectiveness of antibiotics (Bartelme, 2001). Beta glucan is known to alleviate the effects of stress and to help fish recover from exposure to toxins in the water (Bartelme, 2001). 

For more information on the potential benefits of beta glucan for aquarium fish, please see the following article:  

Click here: Advanced Aquarist Feature Article  

Other immune boosters the fish receive in their staple diet include the potent antioxidant beta carotene, found in a red and green Gracilaria, and garlic extract, which is an ingredient in some of the Ocean Nutrition Angelfish formulas.  Together with beta glucan, these natural immune system modulators help reduce stress and keep the community tank healthy.

 Growing Room 

Many of the exotic fish in the Angelfish tank can reach adult sizes well in excess of 12 inches and the 250-gallon community tank is by no means the final destination for such specimens.  Although all of the fish are doing well at their current level of occupancy, that may not remain the case as the juvenile fish begin to reach maturity, and their owner is preparing larger accommodations to deal with that eventuality.  And, since Travis is not a typical hobbyist, he is currently contemplating a closed-system home aquarium of up to 4000 gallons total capacity for this purpose.  That's a whopping 16 times larger than the 250-gallon community tank!  The more spacious home aquarium will be set up in much the same manner as the 250-gallon aquarium but will have all of the elbow room even a fully grown 18-inch Queen Angelfish or football-sized clown Triggerfish needs to be comfortable. 

 And that still leaves plenty of space to add additional specimens to Travis' ever-growing collection of exotic marine fish.  As an avid Angelfish aficionado, he is always on the lookout for rare, hard to find species.  The following amazing Angels are high on his wish list at the moment:

  • Cocos Pigmy Angelfish or Yellowhead Angelfish (Centropyge joculator)

  • Boyle's or Peppermint Angelfish (Paracentropyge boylei)

  • Juvenile West Africa or Guinean Angelfish (Holacanthus africanus).

  • Clarion Angelfish (Holacanthus clarionensis) of non-Mexican origin

Any information on the availability of these or other angelfish rarities would be most welcome.  If you know of a source for any such exotics, please feel free to contact the author ( at your convenience. 

Those are the main features that make this remarkable community tank tick.  When I first learned about this amazing angelfish system, I was immediately struck by certain aspects of this setup.  The first observation to leap out at me was that it appears many marine fish may be much far more euryhaline (i.e., able to tolerate and adjust to a wide range of salinities) than I or many others had previously suspected.  Quite a few fish in the aquarium are from the Red Sea and Indian ocean, which are bodies of water that have a significantly higher specific gravity than normal seawater, yet here they are thriving in an aquarium at 15 ppt and have been doing so for many months! They received no special acclimation whatsoever when they were introduced into the community tank, going from full strength seawater to a specific gravity of 1.011 over a period of approximately 20 minutes.  Yet they're healthy, eating aggressively, their colors are brilliant, and they are growing.  If they are stressed in any way by the low salinity, it certainly isn't apparent from their appearance or their behavior.  The same is true for all of the fish in the aquarium.  It doesn't seem to matter if they are from the tropical Atlantic, Caribbean, Indo Pacific, Red Sea, Indian Ocean, or Australia.  The fish seem to very quickly adjust to the unusually low salinity and remain comfortable at that salinity thereafter.  That's remarkable and worthy of further study.

C. Semilarvatus can be kept in pairs or small groups.  This pair makes a stunning addition to this already stunning collection of fishes.  Photo by Joel Giwojna

But that's not true of all marine fish, of course.  Sharks and Rays (elasmobranchs) and certain clownfish, for example, do not tolerate hyposalinity at all.  And it's way too early to draw any conclusions about what the long-term effects of the hyposalinity may be in this case.  But I am surprised to see that so many different Angelfish, Tangs, andTriggerfish seem to be perfectly happy at a salinity of 15 ppt, at least thus far. 

The lack of aggression in the Angelfish community tank is equally surprising.  How can so many well-armed Angelfish, Triggerfish, and Tangs be confined together in such a limited space without mayhem, murder and chaos on a massive scale? 

No doubt the labyrinth of live rock that offers instant shelter and handy hideouts within fin's reach at all times helps in much the same way that a tank full of feisty Lake Malawi cichlids of different species can be maintained and even breed in a good-sized aquarium with elaborate rockwork.  But I feel the sheer numbers of fish in the community tank also helps to prevent and diffuse any aggression.  For one thing, I believe it keeps the angelfish and tangs from establishing set territories that they would then feel the need to defend.  How can you stake a claim to a piece of turf if other fish are continually moving in and out of your territory and nobody is respecting your claims?  I don't believe the fish can establish fixed boundaries in such a fluid situation and that helps to defuse any hostility. 

Furthermore, with so many fish present, if any of the specimens are inclined to indulge in a little bullying, their aggression is spread out among so many potential targets that no one fish is subject to any significant amount of harassment.  It's the same principle that allows pet dealers to keep dozens of pugnacious damselfish together in the same small aquarium -- none of them can claim a territory and any fin nipping or hostility is so dispersed as to be insignificant.  So they coexist peacefully under those circumstances and maintain an uneasy truce with very little aggression.  I suspect much the same dynamic is playing out in the angelfish community, and that after living together for weeks and months and seeing that there is plenty of food and shelter for all, the other angels are gradually accepted as tankmates at some point in the process. 

Whatever the reasons, all of the 26 Angels, 7 Triggerfish, and dozens of Tangs and butterflies get along together remarkably well.  In fact, when newcomers are added to the community tank, they are often virtually ignored by the big bad Angelfish and temperamental Triggerfish.  The only specimens that seem to regard the new additions as unwelcome intruders are a Chevron Tang (Ctenochaetus hawaiiensis) and a Powder Blue Tang (Acanthurus leucosternon), and even their objections are relatively mild; any halfhearted attempts at persecuting the newcomers by these two tough-guy tangs typically persist only for the first couple of hours.  After the new fish have been in the tank for a few hours, even the chevron and powder blue tang seem to regard them as part of the crew. 

But don't take my word for it -- see for yourself!  The still photographs in this article will give you a glimpse of what I'm talking about, but you need to really see the fish in action to fully appreciate all of the color and activity in the aquarium and how peacefully the fish interact with one another.  This is one aquarium that has to be seen to be believed and, fortunately, the owner has installed a web cam within the aquarium itself that is connected to the same circuit as the aquarium lights, so that anyone with a high-speed modem can marvel at the spectacle any time the tank is illuminated.  Just go to if you want to check out this incredible community tank in all its glory.  I should warn you, however, that Travis' "Angelfish Channel" is far more entertaining than most anything you'll find on television these days.  (If you're a fish lover and Angelfish fancier like me, it can be downright addicting!)  No drooling! 

The Angelfish community tank has been very successful thus far and is certainly an unforgettable sight, but I hasten to emphasize that it is very much an experimental aquarium system.  Quite frankly, Travis and Aquatic Environments are pushing the limits of what's possible with a closed-system marine aquarium.  In the process, they are breaking every rule in the book with regard to stocking densities, blithely ignoring all the recommendations regarding inches-of-fish-per-gallon, and blatantly violating every guide on the compatibility of marine fishes that has ever been devised.  Mr. Carter can tempt fate this way and survive because he has all the resources and expert help he needs to do whatever is required to make his unorthodox system work.

In short, this is not a system the typical home hobbyist should attempt to emulate. But by the same token, if the basics of good aquarium management (maintaining optimum water quality, good nutrition, providing natural surroundings with plenty of cover, and disease prevention) can produce such phenomenal results under the extraordinary circumstances we have been discussing, then just think what a difference they could make for your humble home aquarium with a more reasonable stocking density of fish!  It's the superior aquarium maintenance, feeding regimen, and disease prevention measures that Travis employs which other hobbyists should strive to duplicate.

And although Travis' ultimate Angelfish aquarium may be beyond the reach of most aquarists, the home hobbyist certainly could consider something similar on a smaller scale.  Say a 55-gallon fish-only aquarium with a large sump and an efficient filtration system that houses a community of Damselfish, Dottybacks, Wrasse, Tangs and perhaps a small Humu Triggerfish and a hardy Coral Beauty Angelfish.  Use plenty of live rock and branching coral formations to create elaborate aquascaping and abundant shelter.  Maintain hyposalinity during the high-risk period while the aquarium is being stocked as a precaution and then very gradually return the salinity to normal over a period of at least a week after the tank has been fully populated.  Follow the disease prevention methods we have discussed in this article, provide the fish with a nutritious, varied diet, and maintain optimum water quality, and you, too, can enjoy an aquarium that's alive with color and bustling with activity. <Again, this approach is not recommended for everyone- Ed>

 In part two of this article, we will discuss hyposalinity or osmotic shock therapy in depth and explain when and where it's appropriate and when it should be modified or avoided altogether.

<Editors' note: At Conscientious Aquarist, it is our mission to promote the careful stewardship of the animals that we keep. To this end, we try to present content that embraces this philosophy. As you are now aware, and as Pete Giwojna has stated, the aquarium discussed here seems to break many of the "rules" of the marine aquarium hobby. However, rather than interpreting this article as a "guide" to creating a similar system, we feel that the real message is that careful attention to husbandry techniques can be applicable to  any aquarium system. No one here is recommending that you attempt to stock a system like Travis', yet we do implore you to embrace his philosophy of water quality management, feeding, and long-term planning for your own systems. These are the true keys to success, in our opinion. -S.F./A.C.>


Bartleme, Terry D. 2003.  "Beta Glucan As a Biological Defense Modulator."  Advanced Aquarist Online Magazine, feature article.  Accessed 7 May 2004.

Fenner, Bob.  2003.  “Protein Skimming, Ozone, and UV Use in Marine Filtration”.  Part of The Conscientious Marine Aquarist.  2003.  Accessed 12 December 2003.

Fenner, Bob.  2004.  "Marine Angelfishes, Family Pomacanthidae."  Part of The Conscientious Marine Aquarist online:. Accessed 14 April 2007.

  Giwojna, Pete.  Jun. 2002.  "Ocean Rider: A 'Horse of a Different Color, Part II."  Freshwater and Marine Aquarium

Kollman, Rand.  1998.  “Low Salinity as Quarantine and Treatment of Marine Parasites.  SeaScope.  Aquarium Systems: 1,3.

Lowry, Toby, DVM.  2007: "Quarantine of Marine Fish (Teleost) Using Hyposalinity."

Advanced Aquarist Online Magazine, short takes.  Accessed 21 April  2007. 

Marine Angelfish, Family: Pomacanthidae.  2007.  Part of Dr. Jungle's Animal World: Accessed 7 April 2007.

Travis Carter’s Mega Angel Tank      9/18/19
I thoroughly enjoyed reading Pete Giwojna’s article on Mr. Carter’s tradition- challenging tank! I would love to know if there is any follow up information out there about how this tank progressed long term did Mr. Carter upgrade to a larger system as was alluded to in the article. What was the long term effect of running in hypo?
<Ahh, wish I had a good email addy to ask Pete re. You might try writing him via Ocean Rider in Kona, Hawaii>
Is there any info out there! I greatly appreciate you help and run to WWM frequently for all my fish questions!!! Working on stocking a 650 FOWLR right now!
<Wowzah! Am not a fan of continuous hypo(salinity), but do know of a few service companies, retail, wholesale marine livestock outfits that use it. Some upsides (lower ext. parasite, infectious agent loads, cheaper using less salt, higher dissolved oxygen) and down (diminished "sliminess" and what it provides esp.)>
Best regards,
Steve Offutt
<Cheers, Bob Fenner>
Re: Travis Carter’s Mega Angel Tank      9/18/19

Bob -
Thanks for the prompt reply! Will seek Pete out if possible. Look forward to seeing your presentation at RAP Chicago!
<Ahh, see you there! I just tried to look up OR, now:
Peter used to write informative articles, answer seahorse questions for them. BobF>

Angelfish tank, stkg. mostly... comp. f' as well   9/26/09
Hey there Crew. I have a quick and hopefully easy question for you.
There is an article on your website found here...
It deals with keeping a large volume of fish in a tank. I've read the disclaimers through the article and know it isn't exactly the ideal setup although it was working for the guy who has the tank. I'm curious if you have any more information on the status of the tank? The article is a couple years old, it looks like to me... do you know if things worked out long term for him?
<I do not have any further update, info. re status of this one set up, but can tell you that this sort of seemingly over-crowded, largely angel-system is not unique, has been used several times... mainly in the orient, but also a standard in some east coast U.S. service companies... And can indeed be "done". IF ones mechanicals (filtration et al.) and maintenance are up to par, packing such animals together appears to greatly depress territorial expression... Bob Fenner>

Concerns re Angelfish Article in May/June CA   6/13/07
Have you read this article?
Did you THOROUGHLY read this article?
>Had seen, read it... Don't endorse the apparent philosophy. RMF<
An email came in yesterday about this article. >
I just got done looking through the newest issue. The article "The Ultimate Angelfish Aquarium" really shocked me. The folks at WWM have always stressed the importance of proper conditions for the fish being kept. This article strays so far from that it isn't even funny.
I really used to enjoy reading the informative and knowledgeable advice given but I guess those times have changed.
<It happens to be from someone I know and respect ,and to tell you the truth, after reading the article I tend to agree with him. I am saddened and concerned by Carl's disappointment. I'm not really sure this article belongs in the Conscientious Aquarist Magazine. I will agree that it is an interesting system, but I'm not convinced this is a "success story".
Seems more like of a "disaster hasn't happened yet story". I just don't know if this is something we should highlighting and seemingly endorsing...particularly if the reader fails to read the editors note at the end. A couple of things that I find disturbing. First off this feels a bit like a commercial for Aquatic Environments. It bothers me that this tank has come about due to Travis Carter's passion, but the tank is in a office setting where it is questionable if he has ownership and it is also stated it is left unattended over the weekends. I'm also not walking away with the sense that Travis did a lot of research and investigation before setting up this system. Perhaps he did, but I don't think it is well conveyed by the author.
The article also states that the system is too small many of these fish once fully grown...>
Many of the exotic fish in the Angelfish tank can reach adult sizes well in excess of 12 inches and the 250-gallon community tank is by no means the final destination for such specimens. Although all of the fish are doing well at their current level of occupancy, that may not remain the case as the juvenile fish begin to reach maturity, and their owner is preparing larger accommodations to deal with that eventuality. And, since Travis is not a typical hobbyist, he is currently contemplating a closed-system home aquarium of up to 4000 gallons total capacity for this purpose. That's a whopping 16 times larger than the 250-gallon community tank! The more spacious home aquarium will be set up in much the same manner as the 250-gallon aquarium but will have all of the elbow room even a fully grown 18- inch Queen Angelfish or football-sized clown Triggerfish needs to be comfortable.
<....So he's CONTEMPLATING a system... That's not terribly reassuring.>
<Pete states that the aquarium is 250 gallons and there is an "equally large sump" Copied from the article:>
By equally large, I mean that Aquatic Environments in Minneapolis designed and installed a Maxi-Sump specifically for this aquarium that takes advantage of every inch of space under the tank in order to provide a sump/refugium of maximum possible size. The new sump was custom-made to fit the exact dimensions of the aquarium stand and then slid into place from above before the aquarium itself was installed.
<Pete then goes on to state:>
A minimum of 100 gallons of saltwater are replaced weekly without fail.
The newly mixed saltwater is made from RO/DI water and is preadjusted to the same temperature, pH, and salinity as the main tank before the water changes are performed. This assures that at least 40% of the aquarium water is replaced every week.
<Something is incorrect here. 100 gallons is 40% of 250 gallons, but supposedly the total system volume is much more because of the "equally large sump">
Although this is a fish-only system, the water chemistry in the community tank is monitored and regulated as though it were a reef system to assure that nothing is overlooked. Aside from the basic water quality parameters, the carbonate hardness, total alkalinity, and calcium and phosphorus levels in the aquarium are checked several times a week, which is an important precaution for marine aquarium that maintains a salinity of only 15 parts per thousand. The aquarium is dosed with calcium, magnesium and iodine regularly to maintain optimum levels at all times.
<So the system is dosed with Magnesium and Iodine, but no mention was made of testing for these additives.
What do you think of this long term hyposalinity?
>Again, not a fan. RMF<
I appreciate the editors note at the end, but I think it should at the very least be at the beginning of the article and could/should be worded/written a little more strongly.
Just some of my thoughts... makes me question if this is responsible conscientious aquarium keeping. I am curious your thoughts re...
>What more can I state? I am neither of the co-editors... ScottF and AdamC are... It is up to their discretion what to include/omit... They have >accepted the task/responsibility... and along with this comes accountability. BobF<

Re: Concerns re Angelfish Article in May/June CA   6/13/07
Michelle and all,
Scott and I are both in agreement with the points stated in this conversation, and I agree that the editor's note/disclaimer should be beefed up.
I think one of the major reasons this "slipped through" without more condemnation is because Scott and I both looked at it from our own perspective.... that is (modesty aside for a moment) as well read, experienced and skilled aquarists. I personally would not attempt to maintain a system like that because I don't have the patience and discipline. However, with disciplined maintenance, careful observation of the health of the fishes and acceptance of the fact that fish that "don't fit in" (due to large size, excessively aggressive or timid behavior, etc.) must be removed, it can be done. All that said... it is riskier than a more conservatively stocked system, but none of the fish in the images appear to be underfed, in poor health or beaten up.
Michelle and Bob, would you consider it sufficient to add a beefier and more stern disclaimer to the beginning of the article? If the consensus is that this article is entirely contrary to the WWM ethic, then we should remove it. In my mind, it comes down to whether a bad example can be used to teach a good lesson or if most readers will find the answers they want to hear and gloss over the warnings/admonishments.
<I appreciate this elaboration, and will add to the article itself... Though we may be disdainful to such stocking... this case is not peculiar in many parts of the world... Take a look at Wayne Shen's book... BobF>

Re: More concerns re Angelfish article. Learning From A Bad Example? – 06/14/07
Dear Crew,
<Hi there, Scott F. with you today.>
I live in Recife, Northeast Brazil where reefs abound, but few successful marine aquarists can be found.
Therefore, I have relied on your great service for the bulk of my information since setting up my tanks a year ago.
Thanks to you, I have been quite successful and my systems are my pride and joy.
<We're pleased to have been of service!>
Yesterday, while I showed your online Angelfish article to the local fish shop owner, his first comments were, "the live rock is dead".
<"Dead" in terms of obvious macrofauna, but most likely inhabited by microorganisms and bacteria...Nonetheless, an interesting observation!>
I thought this was a significant observation, considering the tank has been running for eight months and receives regular additions of calcium, magnesium and iodine.
Surely, this has much to do with the low salinity.
Wouldn't it be interesting to see how this tank is doing eight months from now?
<Yes, it would!>
Perhaps then it would be mature enough to serve as an example to conscientious aquarists.
Stephen J. Jones
<Interesting point, Stephen. Long-term stability and success are the true goals of conscientious aquarists. We received some interesting feedback about Pete's article! As indicated in our Editors' note in the piece, we absolutely DO NOT recommend or condone this type of aquarium or the stocking practices demonstrated by the owner. WWM and Conscientious Aquarist have always been about the responsible husbandry and stewardship of aquatic life. However, this article was selected for inclusion in Conscientious Aquarist not to serve as an endorsement of these practices, or as "how to" guide for others to replicate the system. It was selected because we felt that sometimes, there is even a lesson to be learned from a bad example! At best, it may have been thought-provoking, and at worst, it might be offensive-for which we do apologize. Some of the husbandry practices of the hobbyist who owns the featured aquarium were, in our opinion, the only reason that this system was even able to work in the short run. The long-term results will be even more interesting. On the other hand, the shortcomings of the system and it's stocking density were immediately obvious to all of our well-informed readers, such as yourself. In a way, it's gratifying to hear that our readers, the majority of whom embrace our philosophy, recognize that this system is run in a manner contrary to what we preach here on WWM. And that's the point...I don't believe that a single one of the Crew would ever recommend stocking an aquarium in this manner, and I'm virtually certain that none of our readers would attempt such a system. It is our hope that no one interpreted the piece as a tacit approval of the featured system. Hopefully, anyone who found the aquarium featured in the piece offensive or contrary to their sensibilities will continue to dedicate themselves to spreading the WWM philosophy of conscientious husbandry to other hobbyists, for the benefit of the animals that we all cherish. Thank you so much for your feedback. We welcome interaction from our fellow hobbyists! Regards, Scott F.>

How Many Angelfish Can You Fit In...? – 06/16/07
Dear Scott F,
<Hi there!>
Thank you for your prompt and full reply to my observation.
<My pleasure!>
Another thought that crossed my mind regarding that tank, is that the lack of aggression among so many territorial fish may have something to do with a slight discomfort, or "anxiety" also (possibly) caused by hyposalinity.
In other words, you don't pick fights when you're feeling under the weather.
Best regards,
Stephen J.
<I agree that this is a possibility...but I also think that the reason that you're seeing little aggression is that the stocking density is just sooo high in the system. Regards, Scott F.>


Marine Angelfishes on WWM
  Marine Angelfishes, Family Pomacanthidae by Bob Fenner & FAQs on: Marine Angelfishes In General, FAQs 2, Angelfish ID, Behavior, Compatibility, Angel Compatibility 2, Selection, Selection 2, SystemsFeeding, Disease 1, Disease 2Disease 3Disease 4, Angels and Butterflyfishes & Crypt

  The Best Marine Angelfishes for Aquarium Use by Bob Fenner & FAQs

Regional Accounts:

     Two Angelfishes of  the Caribbean, French and Gray by Bob Fenner & FAQs

     Angelfishes of the Tropical E. Pacific/Baja by Bob Fenner & FAQs

     Fiji Islands Angels by Bob Fenner & FAQs

     Angelfishes of Indonesia

     Marine Angelfishes of the Maldives, Indian Ocean & FAQs

     Angelfishes of the Red Sea & FAQs,      

Genera and Species Accounts:

     Marine Angels of the Genus Apolemichthys & FAQs


     Dwarf Angels of the Genus Centropyge Part. 1, Part. 2 by Bob Fenner & FAQs 2, FAQs 3FAQs 4Dwarf Angel Identification, Dwarf Angel Behavior, Dwarf Angel Compatibility, Dwarf Angel Compatibility 2, Dwarf Angel Selection, Dwarf Angel Systems, Dwarf Angel Feeding, Dwarf Angel Disease, Dwarf Angel Disease 2, Dwarf Angel Disease 3, Dwarf Angel Reproduction

       Dwarf Dwarf Angelfishes of the Genus Centropyge; C. acanthops, C. argi, C. aurantonotus, C. fisheri, C. flavicauda, C. resplendens...  by Bob Fenner & FAQs,

        The Bicolor or Oriole Dwarf Angel, Centropyge bicolor  by Bob Fenner & FAQs,

        The Coral Beauty, Centropyge bispinosus, A Sometimes Great, Other Times Dismal Dwarf Angel by Bob Fenner & FAQs, Coral Beauty Identification, Coral Beauty Behavior, Coral Beauty Compatibility, Coral Beauty Selection, Coral Beauty Systems, Coral Beauty Feeding, Coral Beauty Disease, Coral Beauty Reproduction,

         Lemon/y Dwarf Angels, A Couple of Lemons; the True and False/Herald's (nee woodheadi) Centropyges by Bob Fenner & FAQs,

        The Flame Angelfish, Centropyge loricula by Bob Fenner & FAQsFAQs 2Flame Angel Identification, Flame Angel Behavior, Flame Angel Compatibility, Flame Angel Selection, Flame Angel Systems, Flame Angel Feeding, Flame Angel Disease, Flame Angel Reproduction,

         Potter's Angel, Centropyge potteri... a Hard, But Not Impossible Hawaiian Endemic by Bob Fenner & FAQs


     Marine Angels of the Genus Chaetodonoplus & FAQs


     Marine Angels of the Genus Genicanthus & FAQs


     Marine Angels of the Genus Holacanthus & FAQs

       The Queen Angelfish, Holacanthus ciliaris by Bob Fenner & FAQsFAQs 2, Queen Angel Identification, Queen Angel Behavior, Queen Angel Compatibility, Queen Angel Selection, Queen Angel Systems, Queen Angel Feeding, Queen Angel Disease, Queen Angel Reproduction,

       The Clarion Angelfish, Holacanthus clarionensis by Bob Fenner & FAQs,    

       The Atlantic Rock Beauty, Holacanthus tricolor by Bob Fenner & FAQs


     Marine Angels of the Genus  Pomacanthus & FAQs

        The subgenus Arusetta, the Yellow Banded and Asfur Angelfishes, Pomacanthus maculosus and P. asfur by Bob Fenner & FAQs, FAQs 2Arusetta Identification, Arusetta Behavior, Arusetta Compatibility, Arusetta Selection, Arusetta Systems, Arusetta Feeding, Arusetta Disease, Arusetta Reproduction,

            The Emperor/Imperator Angel, Pomacanthus imperator by Bob Fenner & FAQs, FAQs 2, FAQs 3Emperor Angel ID, Emperor Behavior, Emperor Compatibility, Emperor Angel Selection, Emperor Angel Systems, Emperor Feeding, Emperor DiseaseEmperor Disease 2

       The French- Angelfish, Pomacanthus paru by Bob Fenner & FAQs

       The Koran-Angelfish, Pomacanthus semicirculatus by Bob Fenner & FAQsKoran Angel Identification, Koran Angel Behavior, Koran Angel Compatibility, Koran Angel Selection, Koran Angel Systems, Koran Angel Feeding, Koran Angel Disease, Koran Angel Reproduction,

          Subgenus Euxiphipops (genus Pomacanthus) Angelfishes (Navarchus/Majestic, Blue-Face, Six-Striped) by Bob Fenner & FAQs, FAQs 2Euxiphipops Angel Identification, Euxiphipops Angel Behavior, Euxiphipops Angel Compatibility, Euxiphipops Angel Selection, Euxiphipops Angel Systems, Euxiphipops Angel Feeding, Euxiphipops Angel Disease, Euxiphipops Angel Reproduction,

     Genus Paracentropyge Angels, & FAQs,

     The Regal Angelfish, Pygoplites diacanthus by Bob Fenner & FAQs

     The Venustus Angel, Sumireyakko venustus & FAQs,


Featured Sponsors: