- This topic has 3 replies, 2 voices, and was last updated 2 years, 9 months ago by Pete Giwojna.
August 17, 2020 at 4:21 pm #52632desa2590Participant
I was wondering if a 30 hex aquarium is a appropriate size for a could of the larger mustangs I had one a long time ago. It wanted to make sure this still fit as far as what would be suitable to populateAugust 18, 2020 at 5:00 am #52638Pete GiwojnaModerator
Yes, a 30 gallon aquarium meets the minimum size requirements for a large pair of Mustangs (Hippocampus erectus), and tall tanks like your hexagonal aquarium are a good choice for seahorses because the increased depth and hydrostatic pressure can help keep them healthy.
In short, Desa, your 30-gallon hex tank has good dimensions and has very nice water depth to help protect the ponies against gas bubble syndrome, which is very desirable. However, because the surface area in a tall, vertically oriented tank like yours is minimal, you’ll have to be extra careful to make sure the tank has plenty of surface agitation as well as good top-to-bottom water circulation in order to be sure that the tank is well oxygenated and that you don’t have any problems with gas stratification, as explained below in more detail:
The Importance of Surface Agitation
Because the height of the aquarium is an important consideration for a seahorse tank in order to allow the seahorses to mate comfortably during the copulatory rise and to protect them against depth-related conditions such as gas bubble syndrome, many seahorse keepers opt for tall hexagonal or column tanks rather than the usual rectangular aquarium setups. That’s just fine and hex tanks and column tanks can work very well for seahorses providing they are large enough and the aquarist is careful to provide them with good surface agitation in order to assure good oxygenation.
That’s important, because the amount of dissolved oxygen in an aquarium is dependent primarily on three factors: the surface area of the tank, the water circulation in the aquarium, and the amount of surface agitation in the tank. Gas exchange takes place only at the air/water interface or surface of the aquarium, which is where clean oxygen enters the aquarium water and dissolved carbon dioxide is off-gassed, leaving the aquarium. The greater the surface area of the aquarium, the more efficient this gas exchange will be, and the higher the dissolved oxygen levels and the lower the dissolved CO2 levels will be as a result. Not only does keeping the levels of dissolved oxygen high and the levels of dissolved carbon dioxide low make it easier for the seahorses to breathe, it also helps to stabilize and maintain the pH and prevent it from falling. Likewise, good circulation throughout the aquarium will prevent dead pockets or stagnant areas, assuring that all the water in the aquarium passes over the surface for gas exchange on a regular basis. Surface agitation is important because no gas exchange can take place unless the surface tension of the water is broken. Therefore, the better the surface agitation, the more efficient gas exchange becomes and the better the aquarium will be oxygenated.
This is where vertically oriented aquarium such as hexagonal tanks and column tanks are at a disadvantage. The surface area of such tanks is restricted, much reduced from the surface area of a standard rectangular tank of equal water volume. Hex tanks and column tanks thus have less surface area for gas exchange to take place, and it is very important for such tanks to have good aeration and surface agitation to compensate for this drawback. This is especially vital for the seahorse keeper, because our seagoing stallions are very vulnerable to low levels of dissolved oxygen (and high levels of dissolved carbon dioxide) because of their primitive gills structure. So if you will be using a hexagonal aquarium or column design for your seahorse tank, it’s especially important to you to provide good water circulation and surface agitation.
Employing wave makers, devices that automatically alternate the direction of the water flow, and using small powerheads to supplement water movement are all the more important when you are using a tall column tank or hexagonal aquarium. Ordinary airstones and bubble wands can also be helpful for providing surface agitation and improving water circulation, and they will do your seahorses no harm whatsoever as long as they produce relatively coarse bubbles and are positioned where the bubbles cannot be drawn into the intake for the water pumps or filters. Just keep the airstones, air bars, or bubble wands relatively shallow in tall tanks – no more than 20-30 inches deep, and they will help to maintain high dissolved oxygen levels while helping to prevent gas supersaturation.
Without devices such as these to maintain good water circulation from the top of the tank to the bottom of the tank in a vertically oriented aquarium (e.g., hex tanks or column tanks), the dissolved gases in the aquarium can become stratified. When the aquarium water cannot mix efficiently from the bottom of the tank to the surface of the aquarium, stratification will occur, with the highest levels of dissolved oxygen and the lowest levels of dissolved carbon dioxide near the top of the tank, where gas exchange takes place, and the lowest level of dissolved oxygen and the highest level of dissolved carbon dioxide building up near the bottom of the aquarium, where the seahorses tend to hang out. That is not a healthy situation for the aquarium or for the seahorses and their primitive gills, which makes efficient circulation crucial for a tall tank with a restricted surface area.
For these reasons, it’s important for the seahorse keeper who uses a hex tank or column tank to monitor the levels of dissolved oxygen on a regular basis to make sure they remain nice and high. Don’t just sample the water at the top of the tank – be sure to test the dissolved oxygen levels in the water at the bottom of the tank where the seahorses will be spending most of their time as well! We will discuss the use of test kits to monitor dissolved oxygen in more detail in Lesson 4 of the seahorse training manual.
In your case, Desa, I would suggest making sure the 30-gallon tax tank has vigorous surface agitation and then I would position a very small powerhead at the bottom of the aquarium with the water flow directed upwards, so that the powerhead provides continuous water movement from the bottom of the tank towards the top. That will help to assure that the entire aquarium is well oxygenated, and that there are adequate levels of dissolved oxygen at the bottom of the tank as well as at the surface. Just make sure that the intake for the powerhead is well shielded or screened off so that it will be safe for the seahorses.
In general, it’s a very good idea for seahorse keepers to take special precautions when using powerheads or internal circulation pumps in a seahorse tank in order to assure that a curious seahorse does not get its tail injured or damaged by the impeller for the powerhead/pump. Basically, this just means that whenever the intake for a powerhead pump is large enough to allow an unsuspecting seahorse to get its tail inside, it’s a good idea to shield or otherwise screen off the intake, regardless of how strong the suction may be, just to be on the safe side. Often this merely involves positioning the powerhead amidst the rockwork or anchoring it in place with the suction cup where there’s no possibility for a seahorse to perch on the powerhead or wrap its tail around the inflow/intake for the unit.
When that’s not possible, you may need to take more elaborate measures in order to screen off the intake from the pump are powerhead to make it safe for the seahorses, Desa.
For example, here’s how to proceed when using the Hydor Koralia powerheads, which are relatively safe compared to other types of powerheads. For one thing, since they are not impeller-operated, the intake or suction is fairly weak compared to a normal powerhead, and there is therefore no danger that a curious seahorse will have its tail injured by an impeller. Secondly, the “egg” or basket-like structure that covers the powerhead often offers sufficient protection so that an adult seahorse really cannot injure its tail. For example, the gaps in the Koralia 1 are only 1/8 of an inch wide, which is too small for grown seahorse’s tail to fit to the gaps.
Just to be on the safe side, some seahorse keepers will encase the entire egg for a Koralia powerhead in a veil-like material, especially if they have smaller ponies, as explained below:
“I have a Koralia that works great in my anemone tankI have a Koralia that works great in my anemone tank(no seahorses). Just in case I bought a piece of Tulle (bridal veil material) to cover it. I got the purple tulle that looks just like coraline algae. Just cut it into a square and put it over the Koralia and secure the ends with a zip tie. Think of it like a lollipop wrapper-if the pump is the lollipop the tulle is the wrapper and instead of twisting the paper at the bottom like a lollipop you secure with a zip-tie. I have H. fuscus and H.barbouri and they could definetly hitch on the Koralia (and I have the nano) The pump still works great and nothing can get in it.”
The Tulle trick will work just as well for screening the intakes of other types of powerheads or circulation pumps as well, and the bridal veil material is not so fine that it will easily get clogged up or impede the flow through the device.
Finally, Desa, since it has been a long time since you have kept seahorses, I would recommend that you read through the Ocean Rider Seahorse Training Manual before you actually purchased your ponies.
The seahorse training program is very comprehensive, consisting of several hundred pages of text with more than 250 full-color illustrations, and it will explain everything you need to know in order to keep Ocean Rider seahorses successfully in a home aquarium, Desa. We provide a free copy of the seahorse training manual to all first-time buyers and customers to assure that home hobbyists are well prepared to give our ponies the best possible care before they make a purchase. There is no charge whatsoever for this service.
If you would like to receive a free copy of the seahorse training manual, just send me a brief note offlist via e-mail at the following address, and I will send your copy of the Manual to you as an attachment right away:
Best wishes with all your fishes, Desa!
Pete Giwojna, Ocean Rider Tech SupportAugust 18, 2020 at 9:07 am #52641desa2590Participant
Ok I get it so like one or two of the wave pumps on the top? In the past I did under gravel filtration what do you recommend in today’s day and age ? I plan on doing live rock and sand in the bottomAugust 18, 2020 at 3:29 pm #52645Pete GiwojnaModerator
Yes, a wave maker situated at the top of the tank should do the job nicely in order to establish good water flow from the top to the bottom of the tank and back again for a tall setup like yours.
Yeah, be old undergravel filters were foolproof and worked great for seahorse setups, and as long as I vacuumed the gravel bed when performing partial water changes, I had great success with them…
Nowadays, in many cases, my preferred setup for seahorses is a “Seahorse-Only with-Live-Rock” (SHOWLR) system, and this is what I usually advise home hobbyists in that regard:
The one indispensable part of a SHOWLR system is the foundation of live rock. The live rock is the living, breathing, heart and soul of the system, which provides the bulk of the biological filtration as well as some denitrification ability and shelter and habitat for countless critters and microfauna. The porous interior of the rock supports large populations of the beneficial oxygen-loving Nitrosomonas and Nitrobacter bacteria that breakdown deadly ammonia and nitrite into less toxic substances (primarily nitrate). Deeper inside the live rock, where oxygen levels are nil, anaerobic denitrifying bacteria take hold and complete the nitrogen cycle, breaking down nitrate into harmless nitrogen. This helps keep the nitrate levels in the seahorse tank low. As a result, live rock is superior to most other forms of biofiltration, which lack this final anaerobic step and cannot carry out denitrification. This makes live rock doubly good at maintaining optimum water quality.
Equally important, the rockwork provides cover for the seahorses. By this, I mean the rock allows the seahorses to hide and conceal themselves completely whenever they feel the need. Seahorses are shy, secretive creatures that rely on camouflage as their primary means of protection, and if they feel too exposed and vulnerable, it can be stressful for them.
How much live rock is needed for a seahorse tank? Well, that depends on one’s personal preferences and the filtration system in the aquarium. For example, many reef systems rely on live rock and live sand as the only means of biological filtration, along with power heads to provide good water circulation and a protein skimmer for supplemental filtration. In a system like that, where the live rock serves as the primary biofilter, as much as 1-2 pounds of live rock per gallon is needed to do the job. That amount of live rock will provide adequate levels of both nitrification and denitrification for the tank, and that is the maximum amount of live rock anyone would ever consider installing in their seahorse tank. Most seahorse setups need no more than 1 pound of live rock per gallon at the most.
However, if you will have an additional means of biological filtration on the aquarium, then you won’t need nearly that much live rock and you can get by with a small fraction of that amount very nicely. Most seahorse keepers prefer to use an external filter with biological filtration ability along with just enough live rock to provide their tank with stability due to the additional biofiltration and shelter it provides, and for decorative purposes. That way they get many of the benefits the live rock provides but the tank remains less cluttered with more swimming space for the seahorses.
In a case like that, the live rock complements the biofilter due to its ability to provide denitrification (i.e., the conversion of nitrate to nitrogen gas, which leaves the aquarium) and complete the nitrogen cycle. This helps to keep the nitrates low and the supplemental biological filtration the live rock provides gives the aquarium greater stability and a bigger margin for error.
So in an aquarium that has an external filter which provides efficient biological filtration (e.g., a wet/dry trickle filter, bio wheel, or canister filter or hang-non-the-back filter with bioballs or other biological filtration media), there is no minimum amount of live rock that must be used. Such an aquarium has adequate biofiltration ability without the need for live rock. It can therefore include many interesting formations of live rock for shelter and decorative purposes, just a little live rock to provide additional stability and to help keep the nitrates under control, or even no live rock at all. Whatever amount the aquarist prefers is just fine when the live rock is not providing the biological filtration. In such cases, 1 pound of live rock per 10 gallons should suffice.
But the stability and denitrification ability provided by the live rock, and the diversity of life it supports, are always an asset for any aquarium, so nowadays most seahorse tanks include at least some live rock. The abundant copepods and amphipods and other meiofauna that come to populate the live rock provide tasty treats for the seahorses between meals, which our galloping gourmets always appreciate.
To take advantage of the benefits provided by live rock, you can simply select the precured live rock you find most attractive at your LFS and add enough of it to create interesting rock formations that are aesthetically pleasing to your eye. Use enough rock to create some interesting caves, arches, ledges and overhangs, but make sure that the rockwork is very well secured and anchored solidly in place so that there is no instability or danger that the rock formations could collapse.
Despite its beauty, natural appearance and the many benefits it provides, some hobbyists avoid live rock like the plague for fear that they may introduce harmful pests to their aquarium along with the live rock. This is a valid concern since potentially harmful hitchhikers like mantis shrimp, fireworms, aggressive crabs, hydroids and Aiptasia rock anemones are very often unseen and unwanted tenants of live rock. They insinuate themselves throughout the live rock in nooks and crannies, and multitudes of these squatters may have taken up housekeeping in a good-sized piece of rock unbeknownst to the unsuspecting aquarist. They conceal themselves within the labyrinth of rock and often escape even the closest scrutiny undetected.
But with a little care this is one time when aquarists can have their cake and eat it too. There are a number of ways to take advantage of all the benefits live rock provides without risking unleashing an epidemic of tenacious rock anemones or turning Jack-the-Ripper loose in your tank reincarnated in the form of a thumb-splitting Stomatopod.
By and large, bristleworms are beneficial scavengers and sand sifters unless their numbers get out of hand, so a good option for many seahorse keepers is to keep the Aiptasia and bristleworm population in check using some means of biological control. Peppermint Shrimp (Lysmata wurdemanni) love to dine on Aiptasia rock anemones and several of these attractive shrimp will do a fine job of eradicating them from the aquarium. Certain nudibranchs (Berghia sp.) also feed on Aiptasia. Likewise, small Arrow Crabs (Stenorhynchus sp.) will keep the bristleworm population at a manageable number. Any mantis shrimp or aggressive crabs that happen to slip by are generally fairly easy to trap and remove, and commercially made traps are available for that very purpose.
Treating the live rock with a hypersaline dip (or a hyposaline dip) is another excellent technique for ridding it of unwanted pests. This method doesn’t kill the critters outright but merely drives them out of the rockwork so you can selectively cull through them. Another advantage of this method is that leaves all the desirable life on the rocks intact and unharmed.
To use this technique, simply place your newly arrived live rock in an inert container filled with saltwater at a specific gravity of at least 1.045 to 1.050 for several minutes before you introduce it to the aquarium. The saltier the water, the shorter the length of time you need to soak the live rock and the more effective it will be in driving out unwanted hitchhikers. Invertebrates cannot tolerate rapid changes in salinity, so all the mobile inverts in the rock will immediately abandon there hidey-holes and bale out of the rock like rats deserting a sinking ship. After several minutes in this extra-salty bath, the evacuation will be complete, and you can remove the now pest-free live rock and sort your catch. Cull the invertebrates left behind in dipping container, discarding the pests you don’t want while retrieving any of the refugees you might like to add to your system. Several minutes in the hypersalinity is usually enough to drive out all the active invertebrates such as mantis shrimp (Stomatopods), crabs, and assorted worms of every description, yet this brief period of immersion will not harm encrusting organisms or sessile life.
Some hobbyists prefer a low salinity bath to debug their live rock, rather than a hypersaline dip, and some will even briefly immerse the live rock in freshwater to drive out unwanted hitchhikers. This is also an effective technique for eliminating pests from the live rock, but using freshwater may impair the beneficial nitrifying bacteria within the porous live rock if you overdo it, and the organisms that are driven out of the live rock will not survive in freshwater for any length of time, so it’s difficult to cull through them and recover any desirable microfauna, such as copepods and amphipods. Freshwater immersion can also be harsh on desirable encrusting organisms and sessile lifeforms.
The best way to obtain live rock is from an aquarium store in your area that caters to reef keepers. They will have pre-cured live rock available and you can handpick interesting rock formations that are heavily encrusted with pinkish-purple coralline algae for your aquarium. That will also save you the cost of having the live rock shipped to you, which can be considerable because of the weight of the rocks.
Seahorse keepers who want brightly colored seahorses will often choose to confine the live rock to their aquarium sump or refugium, rather than the main tank, particularly if they are unable to obtain colorful live rock with lots of coralline algae. The reason for this is that an aquarium with lots of ordinary brownish live rock can sometimes have an adverse effect on the appearance of ponies with vivid coloration. As we all know, our seagoing stallions will often change coloration in order to better blend in with their background, and that means that they may adopt earth tones in an aquarium that is dominated by drab live rock. Although that’s not a concern with dark colored seahorses, it would be a shame to purchase a bright yellow or orange or red seahorse only to have it assume a brown or beige or sandy or grayish background coloration that matches the live rock. Placing the live rock in the sump or refugium instead of the display tank eliminates this possibility, yet still allows the aquarium to benefit from the greater stability, enhanced biological filtration, and denitrification ability (which helps keep nitrates nice and low) provided by the live rock.
And, of course, situating the live rock in a refugium or sump connected to the main tank also eliminates the possibility of unwanted pests entering the aquarium has hitchhikers on the live rock. So that’s a convenient way to obtain all of the benefits live rock provides without the risk that bristleworms, Aiptasia rock anemones, mantis shrimp or rock crabs or pistol shrimp will gain entry into your seahorse tank along with the live rock. Many seahorse keepers who are worried about such undesirable pests therefore confine their live rock to a sump or refugium, or start out with dried rock that is completely free of such hitchhikers instead.
Okay, Desa, that’s the quick rundown on live rock. If you are concerned about introducing unwanted pests, feel free to omit the live rock from your seahorse setup. Just be prepared to take other measures to keep your nitrate levels in the desired range, such as more frequent partial water changes or maintaining a lush bed of macroalgae that you harvest regularly.
Best of luck with your new seahorse setup, sir! Have you considered taking the free Ocean Rider seahorse training course to make sure that your new aquarium is optimized to provide ideal conditions for the ponies? If you want to give it a try, just send me a brief e-mail with your full names to the following address, and I will get you started out with the first lesson right away:
Pete Giwojna, Ocean Rider Tech Support
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