Dear hobbyist:
You’re very welcome! Okay, that sounds like a sensible decision — taller tanks are very beneficial for seahorses.
Yes, indeed, live rock and live free sand are perfectly successful, and in fact particular method that I have found produces the best results for me is a sort of modified Berlin system featuring LR and LS, as described below. One reason I prefer this method is that it is very versatile and can easily be adapted to suit almost anyone’s needs and interests.
The setup for greater seahorses I prefer, and which most hobbyists favor at this time, is know as a "Sea-Horses-Only-With-Live-Rock" system, or a SHOWLR tank for short. It is simplicity itself, extremely effective for seahorses, and endlessly adaptable. It is suitable for tanks from 5 gallons to 500 gallons, and can be adapted successfully to suit the simplest setups or the most complex, high-tech systems. The primary components of the SHOWLR tank include:
(1) a thin layer of live sand (1/2" to no more than 1" deep) for the substrate;
(2) as much as 1-2 pounds of well-cured live rock per gallon of water;
(3) a quality protein skimmer;
(4) and an external power filter to provide water movement and supplemental filtration; power heads can be added as needed to increase circulation and eliminate dead spots.
Live Rock.
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.
As much as 1-2 pounds of live rock per gallon is recommended if the live rock will be the primary means of biological filtration in the aquarium. That amount of live rock will provide adequate levels of both nitrification and denitrification for the tank. 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.
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 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 1.035 to 1.040 for several minutes before you introduce it to the aquarium. These 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.
Another method for debugging live rock is to immerse it in a small quantity of salt water and leave it unaerated and unoxygenated for a day or two. Active pests such as bristleworms and stomotopods will eventually be driven out of the live rock due to a lack of oxygen, whereas the sessile encrusting organisms in houses will be none the worse for wear.
Aquarium Substrate
A thin layer of oolitic live sand, preferably black, is the ideal substrate for a SHOWLR tank. It is bioactive, aesthetically pleasing, and is a fine-grained sand well suited for the various snails that form an essential part of the cleanup crew for a seahorse tank. I find the dark color shows off my seahorses and macroalgae to great effect and enhances the appearance of tank in general. (As long as it’s fine enough I’ve never had any problems with seahorses "snicking" up sand in the aquarium. They will do so on occasion when feeding off the bottom, but never have any difficulty at all expelling it again as long as it’s fine grained.)
The depth of a shallow sand bed like this is a crucial factor. Too deep, and you risk anaerobic dead spots where deadly hydrogen sulfide gas can form. Too shallow, and there will be less surface area to support beneficial nitrifying bacteria and Nassarius snails and other beneficial burrowers may feel vulnerable and exposed. A bed of live sand 3/4-inch to 1-inch deep is just right for the main tank. A properly layered Deep Live Sand Bed (DLSB) 3-6 inches deep with a full complement of sand shifters also works well with seahorses, but is best confined to a sump rather than the display tank due to the seahorse’s heavy waste production.
Best of luck with your new seahorse setup and your ongoing research into the carrot aquarium requirements of these amazing animals!
Happy Trails!
Pete Giwojna
Ocean Rider, Inc. is an Organic Hawaiian-Based Seahorse Aqua-Farm & Aquarium that Follows Strict Good Farming Practices in Raising Seahorses and Other Aquatic Life.
