That sounds really great, sir! A 75-gallon main tank with a 55-gallon sump/refugium can make an outstanding habitat for seahorses, Joe! Such an aquarium system will have plenty of water volume to offer excellent stability as well as the superior height that is so important for seahorses, and it will provide the ponies with plenty of room to roam and grow.
A crushed coral substrate with a depth of 1 inch should work just fine, Joe. I prefer to use a relatively shallow layer of sand in the main tank of a seahorse setup, rather than a DLSB, because the deep sand bed will detract from the vertical swimming space that is available to the seahorses, and the ponies benefit from the increased water depth that a shallow substrate allows.
I do believe the black lava rock is safe to use in a marine aquarium, sir, and, in fact, that’s the preferred substrate for home hobbyists who set up special culture tanks to raise red volcano shrimp (Halocaridina rubra), also known as red feeder shrimp or Hawaiian volcano shrimp, which make ideal live food treats seahorses.
That’s a very interesting idea to plumb the aquarium so that you return flow will be forced up through the porous lava rock on the left and right-hand side of the tank, which would certainly greatly soften and diffuse the water flow, Joe. It would increase the dissolved oxygen levels in the interior of the lava rock, which would inhibit the growth of anaerobic bacteria somewhat, but there are also plenty of heterotrophic and autotrophic denitrifying bacteria that do not require and oxygen-deficient environment in which to grow, so I don’t think that’s going to be much of an issue at all, sir. (In fact, if you also include a DLSB in the sump area, as I recommend, there’ll be no shortage of suitable strata for anaerobic denitrifying bacteria to thrive as well, and the aquarium should naturally be able to keep the nitrate levels nice and low.)
I don’t have any problem at all with your plan to use the lava rock for about 1/3 of the main tank, along with some live rock to assure that the amphipods thrive in reproduce in the main tank, Joe, and I like the idea of including some live spongy rock from your work tanks, sir.
But I would suggest altering your plan somewhat in one respect for best results with seahorses, Joe. Although a seagrass biotype can be used successfully for seahorses, with your background as an accomplished reefkeeper, sir, I would recommend that you set up the main tank with plenty of soft corals that will thrive without high-intensity lighting or especially powerful water currents, and then set up the 55-gallon sump with a DLSB and a well-planted refugium with lots of macroalgae (Caulerpa, Chaetomorpha, Gracilaria) that you maintain on a reverse photoperiod to the main tank.
This is what I usually advise seahorse keepers regarding the use of sumps, Joe:
The Aquarium Sump or Refugium
There are many advantages to adding a sump to your seahorse setup. For starters, it increases the overall water volume of your system with all the benefits that implies. A good-sized sump can easily double your carrying capacity, increasing your safety margin accordingly. It makes an ideal place to put a protein skimmer, heater(s), air stones, and other equipment so they don’t have to be hidden in the display tank. (A well-designed sump does a great job of trapping and eliminating the microbubbles emitted from skimmers and preventing them from entering the aquarium, and provides an excellent way of increasing the aeration/oxygenation, which is so important for a seahorse setup.) It’s the perfect place to perform additional mechanical and chemical filtration, tailoring the filter media to meet ones exact needs, or to add a calcium or nitrate reactor or even a Deep Live Sand Bed (DLS to your seahorse setup. Because the sump is a large body of water separated from the aquarium itself, it facilitates water changes, dosing supplements, adding top-off water to the tank and other maintenance tasks, all of which can be carried out in the sump without disturbing the main tank or stressing its inhabitants. Entire sections of the mechanical filtration can be cleaned at one time without affecting your primary biofilter, and water changes can be performed gradually without causing stress to the fish or invertebrates. A sump/refugium can also be used to grow a lush bed of macroalgae using a reverse lighting cycle to stabilize the pH and absorb wastes.
To take advantage of these benefits, I suggest adding a two-chambered sump to your tank. This can be accomplished by installing a perforated tank divider across the width of the sump, thereby separating it into two isolated compartments. One side accommodates all of your equipment (in-sump skimmer, return pump, heaters, titanium grounding probe, UV sterilizer, etc.) while the other side can be used to establish a deep live sand bed (DLS with plenty of Caulerpa or Chaetomorpha turf algae. The DLSB/macroalgae side serves as a refugium and will soon become populated with countless critters (copepods, Gammarus and other amphipods, larval crustaceans, etc.). With the Caulerpa and/or Chaetomorpha as an algal filter and the anaerobic layers of DLSB providing denitrification, the aquarist never need be concerned about nitrates or nuisance algae with this type of sump/refugium.
In addition, the biological refugium/sump can be maintained on an opposite light cycle to the main tank to offset the daily fluctuations in pH, photosynthesis, dissolved oxygen/carbon dioxide, and redox levels that otherwise occur in the aquarium. Daily variances in chemical, physical and biological phenomena are a fact of life in aquaria, linked to the light and dark cycles and the diurnal rhythms of captive aquatic systems. As one example, the pH of aquarium water typically peaks after the lights have been on all day at a maximum of perhaps 8.4, only to drop to low of below 8.0 overnight. This is related to photosynthesis and the fact that zooanthellae and green plants consume CO2 and produce O2 when there is adequate light, but reverse that process in the dark, consuming O2 and giving off CO2. Redox levels, available calcium and other water quality parameters are affected in similar ways. Needless to say, these variations are far greater is a small, closed-system aquarium than they are in the ocean, so it’s beneficial to minimize such fluctuations by reversing the photoperiod in the main display and the sump/refugium. This is easily accomplished by timing the lighting in the sump so that the bed of macroalgae is illuminated after dark when the lights on the display tank are off, and vice versa. Just use alternating timers on the main tank and the refugium tank so that when one is on, the other is off. (Other macroalgae require a period of darkness in order to thrive, but if you will be using Caulerpa, it can even be illuminated 24 hours a day around the clock in order to accomplish the same thing.) Voila! Just like that the roller coaster ride is over: no more daily fluctuations in pH or highs and lows in calcium levels, oxygen minima, or peaks and valleys in redox potential.
Because it is separate from the main system yet shares the same water, the sump/refugium can also be used as a nifty acclimation tank for new arrivals or a handy isolation tank for separating incompatible specimens. For seahorse keepers, the refugium compartment of a divided sump or dual chamber sump makes an ideal grow-out tank for juvenile seahorses that have outgrown their nurseries but are still too small to be kept in the main tank. A dual-chamber sump is a very versatile design that lends itself to multiple purposes. Use your imagination.
Okay, Joe, those are my thoughts regarding the use of a sump/refugium four seahorse tank, and I would encourage you to set up something along those lines, sir.
With all of the filtration equipment confined to the sump/refugium, you can then devote the main tank to cultivating plenty of colorful soft corals and polyps that will thrive under less intense lighting and a decent amount of water movement that won’t be too overwhelming for the seahorses.
This is what I normally advise home hobbyists regarding the water flow in their seahorse tanks, Joe:
Water Circulation for the Seahorse tank
Many seahorse keepers are overly conscious of the inactive life style and limited swimming ability of Hippocampus, and have adjusted their flow rates accordingly, resulting in undercirculated tanks with too little water movement. That’s a serious mistake for a small, close-system aquarium.
In actuality, seahorses prefer moderate water movement, including some areas of brisk current, providing there are also sheltered spots and some areas of relatively slack water they can move to when desired. Slack water means comparatively low flow, NOT stagnant conditions! As with any aquarium, avoid dead spots and stagnant areas in the seahorse tank at all costs (Giwojna, unpublished text).
Contrary to popular opinion, seahorses are quite effective swimmers that can hold their own in strong currents as long as sheltered areas are available (Delbeek, Oct. 2001). I have often discussed this matter with professional divers and collectors who regularly encounter seahorses in the ocean, and they report that the horses are often found where you would least expect them — well offshore and thriving in areas with powerful currents. For example, here is how Paul Baldassano, a commercial diver in New York who makes his living collecting sea urchins, describes the behavior of his local seahorses:
“In regard to seahorses in the wild, I occasionally see Hippocampus erectus in the wild while SCUBA diving but never in the places where they are supposed to be. I see them in the open sea far from shore and also in areas with large rocks and very strong currents. The last one I saw was in a channel off the south shore of Long Island New York in water about 12 feet deep. The current was so strong that I had to hold on to the rocks so as not to be swept away. This Hippocampus erectus was having no trouble staying there munching on the abundant plankton. Apparently they find places near the rocks where there is no current because as you know they are lousy swimmers. There is also a large population of seahorses in a similar area in another part of the New York shore, but I think it is best not to divulge that location for obvious reasons (Baldassano, pers. com.).”
Neil Garrick-Maidment, a very successful seahorse breeder in the UK, reports much the same thing, noting that seahorses in the wild seem to thrive amid strong currents:
“Whenever I have dived on Seahorse sites I have always been amazed by the currents and tides that this very fragile looking Seahorse lives in. We often find Seahorses in flat muddy/silt areas nowhere near rocks or weed. These areas are often scoured by strong currents and the Seahorses do well in them and seem completely unperturbed by the current (Garrick-Maidment, pers. com.). In setting up a tank for them I try to remember the feeling I had in those areas and replicate them. I have now started to use wave surge devices, so that the current in the tank, although strong (they seem to thrive in strong currents) varies in its direction (Garrick-Maidment, Jun. 2002).”
Kirk Strawn, who earned his Master of Science thesis studying Hippocampus zosterae in the field, echoes Neil’s thoughts on the matter:
“The aquarist is not giving his seahorses natural conditions when he keeps them in a still-water aquarium. In nature tidal currents, wind, and waves are usually mixing the well aerated surface film water with the deeper water.”
Likewise, Joe Warland, a fish farmer and commercial seahorse breeder in Port Lincoln, Australia, reports he often finds Hippocampus abdominalis perching on the tuna net enclosures at the farm in deep water:
“The Horses that are around the farms have traveled vast distances over plain sand/mud to get to the farms, which are in at least 20 meters of water, and are miles from the nearest land or shallow water (Warland, pers. com.).”
And Jorge Gomezjurado, the Senior Aquarist at the National Aquarium in Baltimore, recommends the following when it comes to water movement:
“I personally believe that current and water dynamics are very important for Syngnathids. In nature they live in areas with active water movement.(i.e., tides in mangrove lagoons and estuaries, coral reefs, kelp forests, etc.). Why don’t we give them the same environmental conditions in captivity? Our small tanks (90 gallons) have large turnovers on an average of 5 gpm (or 300 gph). It is very important that the current is steady and directionally constant, which allows the animals to find a good spot to hold and they will not be pulling in different directions all the time.”
Most seahorse keepers feel it’s best to keep the current steady and nonvarying so they can find slack-water areas and sheltered spots downcurrent to hold in when they want to get out of the current. The more brisk the water flow, the more important this becomes. However, in a large aquarium with low to moderate water movement, alternating currents should not present much of a problem, and would help to provide good circulation throughout the tank.
The point is that, as long as slack-water retreats are available, the greater seahorses can tolerate far more current than most folks suspect and good circulation is as important for a seahorse setup as any other aquarium. What seahorses lack as swimmers is not agility, but rather stamina (Evans, 1998). They can hold their own against strong currents, but not indefinitely, so low flow areas where they can move out of the current and hold when they want to rest must be provided in addition to good circulation.
For example, along with an external power filter, my seahorse setup also has a 200 gph powerhead with a sponge pre-filter positioned right near the top for surface agitation and extra water movement, with additional small powerheads used as needed to eliminate any dead spots along the substrate or behind the rockwork. I like to give my seahorses as much current as they can handle without getting blown around.
In short, if your filtration is not turning over the entire volume of the aquarium a MINIMUM of 5 times per hour, your seahorse setup is undercirculated. With a spray bar return raised above the surface of the water to diffuse the outflow, you can safely achieved much higher turnover rates without producing too much turbulence or current for seahorses. A waterfall return is another good way to diffuse the output from your filter, and also works well for seahorses. There will be an area of relatively vigorous water movement at one end of the aquarium underneath and nearby the waterfall, while the other end of the tank is a relatively low flow area. (By the same token, however, if the filtration system in your seahorse tank is turning over the entire volume of water much more than five times per hour, it may be too overpowering for the seahorses unless it is diffused by a spray bar or waterfall return.)
As with anything, too much of even a good thing can be undesirable, and too much current can overwhelm the limited swimming ability of Hippocampus. One indication that you may have too much water movement in your seahorse tank is if the seahorses are getting buffeted around by the currents, and whisked away uncontrollably when they tire of fighting the current. Or alternatively, they may stay perched in one place all the time and refuse to swim around and explore their tank for fear of getting swept away by the current if they relax their grip on their hitching posts. So you can get a pretty good gauge of how well the seahorses are able to cope with the water movement than their tank by observing how the current affects the swimming ability.
Likewise, if a mated pair of seahorses is consistently spilling eggs during the copulatory rise, that’s another pretty good indication that there may be too much turbulence or water movement in the upper reaches of their aquarium.
If the seahorses are having difficulty tracking their prey and eating because the current whisks the frozen Mysis past them too quickly to target it accurately and slurp it up, that’s another red flag. Often that situation can be corrected simply by adjusting the output from your filter to reduce the current during feeding time or turning it off altogether while the seahorses are eating.
But as long as your seahorses aren’t getting buffeted around, aren’t routinely dropping eggs during disrupted mating attempts, and aren’t having difficulty targeting their prey and eating, there’s really no such thing as too much water movement. In general, the stronger the water flow, the more important it is to keep the water currents steady and unvarying so the seahorses can establish holding areas in the sheltered spots and low-flow zones without getting blindsided by unpredictable currents. Just make sure your seahorses are not getting trapped against overflows and be sure to screen off the intakes for any powerheads. Powerheads can be switched off at feeding time, if necessary.
To sum up the above and quantify everything, you generally want the filtration system for seahorse tank to be able to turn over the entire volume of the aquarium about five times every hour in order to provide adequate circulation throughout the whole tank. So for the 14-gallon bio cube, the filtration system should put out about 70 gallons per hour in order to provide optimum conditions for the seahorses. But if the output from the filtration system exceeds 100 gallons per hour, the seahorses may have difficulty with the powerful currents and you may need to make modifications cents you’re going to have too much current and turbulence for the seahorses otherwise, Joe.
This is what I typically advise home hobbyists who want to keep seahorses in reef systems such as bio cubes or with live corals, Joe:
Live corals are a different matter altogether, and you must observe some special precautions when selecting corals for a seahorse tank. Here are some suggestions regarding what specimens do well with seahorses and which should be avoided, if you will be keeping live corals with your ponies or maintaining a reef biotype for them:
Seahorse-Proofing the Reef Tank
When designing a reef tank that will include seahorses, one must anticipate the different ways they might be injured in such a setup and then take precautions to prevent them from coming to harm. The process of rendering your reef system seahorse safe is much like the measures new parents take to childproof their house when they are expecting their first child. Intake tubes for the filters should be shielded, siphon tubes should be equipped with filter baskets or screens, and so on…
For instance, when powerful water movement is combined with overflows, there is a risk that seahorses could become pinned against an overflow or even go over it (Delbeek, Oct. 2001). Therefore, in the seahorse reef, overflows must be baffled and/or screened off, or the water flow should be adjusted sufficiently to prevent that from happening.
Likewise, although seahorses have no problem with strong currents in the wild, in the confines of aquarium, it is possible for them to come in contact with stinging corals if they are struck by a sudden powerful wave or surge, or are overwhelmed by a strong, unexpected current (Delbeek, Oct. 2001). The hobbyist needs to take this into consideration when placing water returns and corals in the seahorse reef (Delbeek, Oct. 2001). If possible, keep the water currents steady and unvarying so the seahorses can establish holding areas in the sheltered spots and low flow zones without getting blindsided by unpredictable currents.
One good way to accommodate both the needs of corals that prefer brisk currents and the seahorse’s need for slack-water retreats is to create tall rock formations a foot or two down current from the strongest water flows to intercept and deflect or divert that strong flow of water, creating eddies and slack-water zones where there is relatively little water movement down current. Seahorses will hold in these low flow areas when they want to move away from the current, so it’s a good idea to position convenient hitching posts in the lee or down-current side of such formations..
Another excellent way to accomplish the same thing is to use small powerheads to create and direct current wherever needed. A properly positioned powerhead can thus bathe your prized Acropora formations in a brisk water stream precisely without generating too much water movement elsewhere in the aquarium. Just be aware that powerheads can become death traps for seahorses if their intakes are not properly shielded or screened off, and take the necessary precautions (Delbeek, Oct. 2001). Carefully conceal the intakes amidst the rockwork where they will be completely inaccessible to seahorses, otherwise shield them, or screen them off with a sponge prefilter.
In short, the hobbyist who wants to keep seahorses in a reef system must be willing to make some concessions and modifications to accommodate their special needs nonetheless. For example, the reef keeper must be willing to limit himself to corals and invertebrates that meet the following criteria:
1) Avoid any stinging animals with powerful nematocysts. This means fire corals (Millepora spp.) and anemones should be excluded from the seahorse reef, and any corals with polyps that feel sticky to the touch should be used with discretion and only after careful planning. When a seahorse brushes up against them or attempts to perch on them, the nematocysts or stinging cells of these animals can penetrate the seahorse’s skin and damage its integument. Needless to say, this causes pain and discomfort and can leave the seahorse vulnerable to secondary bacterial and fungal infections, which may take hold at the site of injury. Short polyped stony (SPS) corals are generally fine, but large polyped stony (LPS) corals should be regarded with caution, as discussed in more detail below.
2) Water movement and circulation must be managed as previously described. Corals that require powerful surge or overly strong water currents could overtax the limited swimming ability of Hippocampus unless slack water areas the seahorses can retreat to when needed are also provided.
3) The corals must be able to withstand being used as hitching posts by the seahorses from time to time; that is, they cannot be so delicate that having a seahorse’s grasping tail anchored around them could cause them any harm. For instance, soft corals may retract their polyps when a seahorse perches on them. This can be harmful to their health if it becomes a chronic problem, because many corals rely on their polyps to absorb light and convert it to energy via photosynthesis. Be sure to watch any soft corals and hermatypic corals to make sure they are not closed up for extended periods. Normally, they adjust to the seahorses’ presence and unwelcome attention after a while, and remain contracted only briefly after each contact. After repeated exposures to grasping tails, each such incident elicits a weaker response, so they tend to extend their polyps sooner and sooner after being disturbed (Delbeek, Oct. 2001).
4) Avoid Tridacna clams and similar bivalve mollusks. Sooner or later a seahorse will perch on them with its tail between the valves and the clam’s powerful adductor muscle will clamp down on it like a vise. At best this will be a very stressful experience for the unfortunate seahorse, since it can be the devil’s own business trying to persuade the stubborn mollusk to release its struggling victim! At worst, it can result in serious injury or permanent damage to the seahorses tail (Giwojna, unpublished text).
5) Beware of unwanted hitchhikers that may have come in on your live rock unbeknownst to you and which can harm seahorses, such as fireworms, mantis shrimp, or Aptasia rock anemones. When setting up a reef system for seahorses, it’s a wise precaution to pre-treat your live rock with a hypersaline bath to drive out such pests beforehand because they can be very difficult to remove or eradicate once they make themselves at home in your aquarium (Giwojna, unpublished text).
As long as the specimens you are considering for your seahorse reef satisfy these requirements, anything goes! Some of the good and bad candidates for such a reef system are discussed below:
Soft corals have very little stinging ability and generally make good choices for a modified mini reef that will include seahorses (Delbeek, Oct. 2001). This includes most mushroom anemones (corallimorpharians). However, as Charles Delbeek cautions, “One notable exception is the elephant ear mushroom anemone (Amplexidiscus fenestrafer). This animal is an active feeder on small fish and will envelope them whole with its mantle then slowly digest them by extruding its digestive filaments into the space created. No small fish are safe with these animals in the tank (Delbeek, Oct. 2001).”.
Hippocampus also does very well with zooanthids and colonial polyps in general. But the hobbyist must be sure to observe a couple of precautions when handling the zoanthids and placing them in your aquarium.
First and foremost, many of the commonly available Zooanthus (button polyps) and Palythoa (sea mats) species contain a very toxic substance in their mucous coat known as palytoxin, which is one of the most poisonous marine toxins ever discovered (Fatherree, 2004). Palytoxin can affect the heart, muscles, and nerves, resulting in paralysis or possibly even death, and many hobbyists have reported numbness, nausea and/or hallucinations after merely touching these corals (Fatherree, 2004). When you handle zoanthids and palythoans, you cannot help picking up some of their protective slime on your fingers, and so much as rubbing your eye, picking your nose, or a small cut on your finger can be enough to land you in the hospital. When handling Zooanthus are Palythoa species, it’s very important to wear disposable latex gloves, avoid touching your mouth or eyes, and carefully dispose of the gloves immediately afterwards (Fatherree, 2004).
Secondly, zoanthids and other soft corals such as mushrooms may wage border battles if you place them in close proximity to each other (and the zoanthids almost always lose out to the mushrooms in these skirmishes). So be sure to allow adequate space between the colonies. Some rapidly growing Zooanthus colonies can be aggressive to soft and stony corals alike as they rapidly spread over the rockwork, but in general they are quite peaceful, and you can always slow down their rate of growth by reducing the nutrient loading in the aquarium.
Other low light corals that should be suitable for a seahorse reef include genera such as Cynarina, Scolymia, as well as non-photosynthetic gorgonians such as Subergorgia and Didogorgia, and perhaps wire corals such as Cirripathes spp. (Delbeek, Nov. 2001).. However, supplemental feedings of zooplankton may be required to maintain these corals in good health.
The hard or stony corals fall into two categories depending on the size of their polyps. The small polyped stony (SPS) corals have tiny polyps that extend out of minute openings in the stony skeleton, and generally have weak stings that should not pose a threat to seahorses. Depending on conditions in the tank, SPS corals such as Acropora, Montipora, Pocillipora, Porities, Seriatopora and Stylophora can be tried freely at your discretion (Delbeek, Oct. 2001).
The large polyped stony (LPS) corals, however, are generally best avoided altogether. These include genera such as Catalaphyllia, Cynarina, Euphyllia and Trachyphyllia that have large fleshy polyps which often have tentacles equipped with powerful stinging cells. The Euphyllia and Catalaphyllia have the most powerful nematocysts among the LPS corals, and can deliver stings that are stronger than most anemones (Delbeek, Oct. 2001).
Some of the soft corals and stony corals that generally do well with seahorses in a modified reef tank are listed below. (By no means is this intended to be a comprehensive list, but rather just a few examples of suitable corals to serve as general guidelines when stocking a reef tank that will house seahorses):
Finger Leather Coral (Lobophyton sp.)
Flower Tree Coral – Red / Orange, (Scleronephthya spp.)
aka: Scleronephthya Strawberry Coral, or Pink or Orange Cauliflower Coral
Christmas Tree Coral (Sphaerella spp.)
aka: the Medusa Coral, Snake Locks Coral, or French Tickler
Cauliflower Colt Coral (Cladiella sp.)
aka: Colt Coral, Soft Finger Leather Coral, Seaman’s Hands or Blushing Coral.
Toadstool Mushroom Leather Coral (Sarcophyton sp.)
aka: Sarcophyton Coral, Mushroom, Leather, or Trough Corals.
Bullseye Mushroom Coral (Rhodactis inchoata)
aka: Tonga Blue Mushroom, Small Elephant Ear Mushroom (rarely)
Clove Polyps (Clavularia sp.)
Stick Polyp (Parazoanthus swiftii)
Green Daisy Polyps (Clavularia sp.), Indonesia
Orange & Green Colony Button Polyps (Zooanthus sp.), Fiji
Pulsing Corals (Xenia spp.)
Red Ricordea (Ricordea sp.), Indonesia, occasionally Solomon Islands
Lavender Hairy Mushroom (Actinodiscus sp.), Tonga
Pimpled Mushroom (Discosoma sp.), Indonesia
For more information regarding seahorse-safe fish, corals, and other invertebrates, see Will Wooten’s online Compatibility Guide at the following URL:
Lighting for a Seahorse Reef
If at all possible, metal halides should be avoided for a reef tank that will include seahorses. In addition to providing high-intensity lighting, the metal halides also tend to generate a lot of heat, and as you know, heat stress can be very detrimental to seahorses. Most of the subtropical/tropical seahorses do best at temperatures of around 73°F-75°F (23°C-24°C); so avoiding temperature spikes above 80°F (27°C) is very important. This can be very difficult to manage with metal halide lighting. In addition, seahorses don’t like excessively bright light and they may go into hiding, seeking shaded areas amidst the rockwork, if the lighting is too intense for their comfort level. And the seahorses won’t look their best and brightest under metal halides because they will produce excess melanin (black pigment) in order to protect themselves against the harmful ultraviolet radiation they associate with intense light, and darken as a result. For instance, Jorge Gomezjurado reports “…I have exposed yellow seahorses to strong metal halide and they have turned black in few hours.” So it would be a shame to display brightly colored seahorses under metal halide lighting in a small, close system aquarium.
All things considered, power compact lighting is a better alternative for a seahorse reef. I prefer the power compacts because they allow me to provide my seahorses with a natural day/night period that includes twilight periods at “sunrise” and “sunset.” To accomplish this, I like the power compact (PC) light fixtures that include two tubes — one actinic and one daylight fluorescent — with dual ballasts so that each ballast can be placed on a separate automatic timer. I like to have the bluish actinic come on before the daylight tubes and stay on after the daylights go off, thereby providing a simulated dusk and dawn (Giwojna, unpublished text). This is important for seahorses since they conduct most of their courting and breeding in the early morning hours under twilight conditions. It’s a neat effect and fish and invertebrates can then anticipate “lights out” rather than being plunged into total darkness at night or suddenly thrust into bright light in the morning. I also adjust the timers to lengthen or shorten the daylight periods in accordance with the changing seasons. I find that maintaining a natural cycle this way aids reproduction (Giwojna, unpublished text).
Basically, I find PC lighting to be a good compromise for a seahorse system. Power compacts provide plenty of light for macroalgae or the seahorse-safe soft corals in a modified reef system without being too bright or generating too much heat, and the dual ballast system allows for a natural day/night rhythm that changes with the seasons. The resulting dusk and dawn facilitate courtship and help the seahorses maintain a natural reproductive cycle (Giwojna, unpublished text).
Although they are very costly, the new Solaris LED Illumination Systems are another good option for a seahorse reef. The Solaris LEDs can provide the spectrum of light and intensity needed by light-loving corals without the same concerns regarding overheating that make metal halides undesirable, and that’s a huge plus for the seahorse keeper. Aside from generating less heat, they also provide very considerable energy savings and the longevity of the LED is also superior to metal halide lamps. Best of all, the flexibility and adjustability of the Solaris LED Illumination System allows you to independently set the lights to duplicate sunrise, daylight, cloud cover, sunset, and even the lunar cycle. They certainly are very expensive, but they have some wonderful advantages over the conventional metal halide lighting, particularly for seahorses. However, because of the cost factor, I prefer PC lighting for a seahorse tank with live corals myself.
Of course, for seahorse keepers who do not have live corals in their corrals, standard fluorescent bulbs or tubes are more than adequate. For all intents and purposes, you really can’t go wrong no matter what lighting system you chose as long as you avoid overheating and provide both shaded areas where your seahorses can escape from light altogether and well-lit areas where they can bathe in the light as they please.
One good way to accomplish that is to keep the coral and inverts that require stronger lighting at one end of the tank, which is brightly illuminated, and keep the other end of the tank shaded to accommodate the seahorses, reserved for corals that don’t need high-intensity lamps. If need be, you can also provide shaded areas by positioning sections of aluminum foil atop your aquarium that are the right size and shape to cast shadows where you want them below. You will find your seahorses will move into and out of the light often, seeking the comfort level that suits them at the moment.
And this is what Charles Delbeek has to say about keeping seahorses in reef systems, Joe:
There has been a lot of interest lately in keeping sea horses in reef aquaria. Although it is possible to do so, there are some things that need to be taken into consideration. Most reef tanks that house corals also have a great deal of water movement. When combined with overflows, it is not uncommon for sea horses to be trapped against or even go over, overflows. Powerheads are also often used and can be death traps for sea horses if the intakes are not properly screened off. To keep sea horses in reef tanks one really must foresee all the possible ways that they could be injured and to take precautions against this happening.
Many corals are powerful stingers, but these belong mainly to the stony coral families. Most soft corals have very little stinging ability and will not harm sea horses. However, since sea horses can grasp onto soft corals with their tails they can cause the coral to retract its polyps. This can be a problem if the coral relies on its polyps to capture light to provide the energy it requires to survive. Fortunately in most cases, the coral will habituate to the constant irritation caused by the sea horse and will not retract its polyps as frequently as in the beginning. The observant aquarist should keep an eye on their soft corals to insure that they are not remaining closed for long periods of time.
In the case of stony corals there are two main groupings to be considered. The small polyped stony (SPS) corals consist of genera that have small polyps that extend out of very small openings in the skeleton. These would include genera such as Acropora, Montipora, Pocillipora, Porities, Seriatopora and Stylophora. These SPS corals are generally considered to be weak stingers and should not irritate sea horses very much. However, the same precaution I mentioned for soft corals also applies to SPS corals. The second major grouping are the large polyped stony (LPS) corals. These include genera such as Catalaphyllia, Cynarina, Euphyllia and Trachyphyllia that have large fleshy polyps often with tentacles that can have powerful stinging cells. Of these the Euphyllia and Catalaphyllia are the strongest stingers, and any sea horses placed into tanks with these corals should be carefully observed.
Despite what many people think, sea horses are quite effective swimmers and can hold their own in strong currents. However, in the confines of an aquarium, it is not impossible for them to come into contact with stinging corals if suddenly caught in a very strong current. The aquarist needs to take this into consideration when placing water returns and corals in the aquarium. People have been keeping fish with corals for several years now and the instances where fish have been taken by corals are few and far between, but it does happen occasionally. Sea Horses, like any other fish, have a natural ability to avoid most powerful stinging corals, and the slightest touch is enough to reinforce this natural avoidance behaviour.
Other invertebrates that sea horses should do well with include zoanthids, corallimorpharians (mushroom anemones), sponges, sea cucumbers, shrimp and the smaller detritus or algae feeding snails, worms and crabs. One notable exception is the elephant ear mushroom anemone (Amplexidiscus fenestrafer). This animal is an active feeder on small fish and will envelope them whole with its mantle then slowly digest them by extruding its digestive filaments into the space created. No small fish are safe with these animals in the tank.
Okay, Joe, that’s the quick rundown on keeping seahorses in a reef tank that will include live corals. Having explained all of the above, I should also again point out that Mustangs or the Sunbursts (Hippocampus erectus) often thrive in suitable reef tanks, where they benefit from the optimum water quality, natural surroundings, and abundant copepods and amphipods in typical well-established reef systems.
Like most large tropical seahorses, Mustangs and Sunbursts are comfortable at stable water temperatures within the range of 72°F-77°F, but they may begin to experience heat stress and associated health problems when the water temperature in the aquarium approaches 80°F or above for any length of time. As long as your aquarium chiller can maintain stable water temperatures around 75°F-77°F, I believe Mustangs and Sunbursts (Hippocampus erectus) would do very well in a 75-gallon modified reef tank as explained above, Joe, as long as they are kept with compatible corals and the water temperature and water flow is suitable for the seahorses. They occur naturally in reefs and sponge beds in the wild, as well as mangroves and seagrass habitats, and are ideal for first-time seahorse keepers, as explained below.
What seahorses are best suited for beginners?
If these will be your first seahorses, then I can heartily recommend Ocean Rider Mustangs and Sunbursts (Hippocampus erectus), which are ideal for beginners. Commonly known as the Lined Seahorse or the Northern Giant or Florida Giant, Hippocampus erectus was the first seahorse to be commercially raised for the aquarium hobby. Mustangs and Sunbursts have been captive-bred and raised for more generations than any other seahorse, and have now achieved a level of domestication that makes them better adapted to aquarium conditions and life in captivity than other seahorses. The Ocean Rider aquaculture facility in Hawaii that raises H. erectus selects them for traits such as adaptability, vigor, disease resistance, fast growth and aggressive feeding habits — traits that increase the fitness of each line over time. After numerous generations of strengthening and improvement, the current breeds of farm-raised erectus are tough as nails. Very hardy and very impressive, Mustangs and Sunbursts are great choices for a novice seahorse keeper who is still learning the ropes. They are very adaptable and have led the on-going trend toward keeping captive-bred seahorses only. Simply put, more hobbyists keep captive bred erectus than any of the other greater seahorses, and rightly so.
Mustangs are impressive animals. They are large, robust, deep-chested seahorses that can reach well in excess of 7 inches in length when fully grown. They tend to be cryptically colored, and often show earth tones such as beige, russet, charcoal black, gray, brown, ochre or olive over an underlying pattern of fine parallel lines that run down their necks and across their chest (Giwojna, Jun. 2002). White blazes, blotches, saddles, triangles, and diamonds are common markings for captive-bred erectus (Giwojna, Jun. 2002).
Seahorses are one fish that can become a true pet, and I’m convinced this is because they are more intelligent than most fishes. The highly domesticated Mustangs and Sunbursts are real personality fish and many of them actually enjoy being handled. Unlike most other fish that back off when you approach the aquarium and flee in terror if you place your hand in the tank, seahorses soon learn to recognize their keeper and will come out to meet you. They quickly learn to take food from your fingers, and as you will discover, having your pet ponies literally eating out your hand is a very rewarding experience. When one of these shy, enchanting creatures — whose very survival in the wild depends on concealing itself from predators at all times — comes trustingly up to the surface to eat right out of your palm, it’s a thrill you won’t soon forget. The training sessions and daily feedings required for this tend to forge a close, personal relationship between the aquarist and his charges, and hand-fed seahorses often become special pets. Many times they will even include you in their daily greeting, flashing their recognition colors and parading back and forth and at the front of the tank, performing their dancelike displays for your benefit.
The first pair of captive-bred seahorses I ever owned were Mustangs, and my ‘stangs quickly learned to recognize me as their feeder, whereupon they would often interact with me at dinnertime by turning on their greeting colors. My original pair are still going strong several years later, and I have watched them go through a number of color phases from month to month. One has settled on gray-green as its base coloration for the moment, and the other ranges between rust, burnt umber, and orange, but always with contrasting beige bands (Giwojna, Jun. 2002). Last season, the male adopted a rich ochre yellow as his everyday attire (still with the same beige bands, though), while the female displayed a dark purplish ensemble with definite greenish highlights. When courting, they consistently brighten to a pearly white and a creamy yellow respectively (Giwojna, Jun. 2002). They make a handsome couple, and I find my erectus to be very attractive specimens in all their guises.
I set up my pair of these spirited steeds in a brand-new 30 gallon (tall) aquarium all their own, and that tank has been my most entertaining, trouble-free exhibit ever since. With a simple setup like theirs, I prefer to target feed my seahorses. That allows me to observe them closely on a daily basis, monitor their health, keep track of exactly how much each specimen is eating, and remove any leftovers immediately.
Led by the female — by far the bolder and most outgoing of the two — the Mustangs were soon literally eating right out of my hands. (I know, I know — sensible aquarists should always strive to keep their mitts out the aquarium as much as possible, but handfeeding is a thrill I find difficult to resist, and hey — nobody ever said I was sensible!) Of course, I’m very well aware of the risks involved and extremely diligent about taking all the necessary precautions beforehand. And besides, there are major advantages to handfeeding that more than offset any minor risks.
For one thing, the seahorses seem to enjoy the experience every bit as much as I do. They head for the feeding station as soon as I approach the tank, a series of color changes betraying their excitement, and queue up at the dinner table looking their best and brightest. Of course, they both try to snap up the first morsel — even pair-bonded ponies are not big on sharing or waiting turns — so I no longer offer them one mysid at a time. I offer them a handful of individually thawed Mysis in my upturned palm instead. They know the drill and happily perch on my fingers while snicking up the shrimp as fast as they can.
Secondly, feeding your seahorses by hand permits the aquarist to conduct a close-up, daily inspection of every specimen in his tank, and I like to use the opportunity to give ’em a good once over. These detailed examinations make it difficult not to notice any subtle changes in my seahorse’s appearance or behavior that might signal impending problems with disease or the water chemistry. That’s a big advantage, since the sooner such potential problems are detected, the easier they are to cure or prevent, and I recommend other hobbyists do
Take a moment to enjoy the show when feeding your seahorses. Make sure they’re all eating well, and use this opportunity to look them over closely for wounds, injuries, or signs of disease. Seahorses are natural-born gluttons. Ordinarily, these galloping gourmets are ALWAYS hungry, so when a seahorse is off its feed, that’s often an excellent early indicator that something’s amiss in the aquarium. Early detection of a potential problem can be the key to curing it, so it’s a good idea for the alert aquarist to observe his prize ponies while they put on the ol’ feed bag. Make sure they all show up for mess call, are acting normally, and have a well-rounded abdomen when they’re done eating. Handfeeding makes it hard to miss when one these chow hounds is off its feed, tipping off the alert aquarist to a potential problem.
Best of all, handfeeding is pure, sure-fire, 100% unadulterated fish-keeping fun! Feeding time for my seahorses is always a high point in my day. Having your pet ponies literally eating out your hand is a very rewarding experience. These daily feedings tends to forge a close, personal relationship between the aquarist and his charges, and hand-fed seahorses often become special pets.
As much as feeding time brightens up my day, I have no doubt it livens things up for my seahorses even more. They genuinely appear to enjoy interacting with me, and I believe in enriching their captive environment as much as possible. No doubt it’s the food they’re looking forward to, not the food giver, but our daily encounters are always eagerly awaited and they like to linger on my hand long after all the food is gone. They would allow me to lift them out of the water when I withdraw my hand if I didn’t gently shoo them away first.
The only thing I don’t like about handfeeding frozen Mysis to my seahorses is the obligatory fast day. The problem with fasting is that the Mustangs don’t seem to realize it’s good for them — that it’s absolutely in their own best interests, essential for their long-term health. Whenever I make an appearance on fast day, they insist on parading back and forth in front of the glass in their greeting colors, begging for a handout. Before my butt hits the upholstery, both of them will be dancing at the feeding station, impatiently awaiting their gourmet shrimp dinner. When it doesn’t materialize, they forlornly abandon their post at the lunch counter, and come up to stare at me through the front glass. When I still don’t take the hint, the female paces back and forth at the front, looking her brightest and most conspicuous, as though trying to attract my attention, while the male reverts to his drab everyday attire and dejectedly resumes his futile vigil at the feeding station. If not for their well-rounded cross-sections, one would think they were dying of hunger, making it difficult to resist their puppy-dog antics. Just sitting there ignoring them makes me feel like a first-class heel. Sheesh — talk about your guilt trips Dang! I hate fast days.
I feel Hippocampus is intelligent enough to become bored or jaded in captivity at times, and for this reason I try to provide a little behavioral enrichment for my seahorses whenever possible. The handfeeding sessions I’ve already described are an example of this, and I also try to provide my seahorses with live foods regularly so they have an opportunity to experience the thrill of the hunt and the chase once in a while as they do in the wild.
In short, I’m sure your friend and his wife would enjoy a pair of Mustangs and/or Sunbursts as much as I enjoy mine, Joe. Sunbursts are very similar to Mustangs in most respects, including their hardiness, and will even interbreed with them freely; the main difference is that the Sunbursts tend to be even more brightly colored, as their name implies. They are predisposed to display sunset colors (shades of yellow, gold, peach, pumpkin, amber and other shades of orange) when conditions are to their liking.
Okay, that’s the quick rundown on the Ocean Rider Mustangs and Sunbursts, Joe, which I think maybe your best option under the circumstances. They do well with all soft corals and many SPS corals as well as some LPS corals.
Please note that the Ocean Rider strain of red banded pipefish (Doryrhamphus dactyliophorus) are also reef dwellers by nature that would do very well in suitable modified reef tank.
Aside from the Mustangs and Sunbursts (Hippocampus erectus), other Ocean Rider seahorses that would thrive in a 75-gallon aquarium with a 55-gallon sump/refugium include Fire Reds, Sun Fires, and Pintos, as well as Barbs (Hippocampus barbouri), Joe.
Best wishes with all your fishes (and invertebrates), sir!
Pete Giwojna, Ocean Rider Tech Support