sea ranch

Dear hobbyist:

Assuming that your aquarium will be a dedicated seahorse tank and not a community tank, and that you’ll be keeping captive-bred seahorses such as Mustangs or Sunbursts (Hippocampus erectus) of average size, the suggested stocking density under those circumstances is about one pair per 10 gallons of water volume. So a reasonable number of average size Mustangs (or Sunbursts) to keep in a 20-gallon aquarium is a total of about two pairs or four individuals. If you are new to seahorses, then I would recommend starting out with one pair of seahorses and then adding another pair after a few months, once you’ve had a chance to learn the ropes and gain a little viable firsthand experience keeping these amazing aquatic equines.

Of course, you’ll need to install a filtration system, cycle your aquarium, and decorate your tank before your Sea Ranch will be ready to support any seahorses at all. And when the big day finally arrives and you are finally ready to begin filling up the old corral with thoroughbreds, be sure to remember the three golden rules that should always guide your actions when stocking your seahorse setup:

I. Under stocking is ALWAYS better than over stocking. Always! That is the one immutable law that governs the seahorse-keeping universe, and if you violate it, the aquarium gods will exact swift and terrible retribution!

II. When in doubt, under stock. Don’t push your luck! If you have any doubt whatsoever as to whether or not your system is running at capacity, it probably is. In such a situation, you MUST err on the side of caution.

III. Don’t mess with success! If your seahorse setup has been running smoothly and trouble-free for a prolonged period at it’s present level of occupancy, try to resist the temptation to increase your herd. Why risk upsetting the balance in a system that has settled into a state of happy equilibrium? Rather than risk overcrowding an established tank, consider starting up a new aquarium when the urge to acquire some new specimens becomes overwhelming.

When stocking your aquarium, consider these golden rules to be your commandments. Obey them, and your system should flourish. Surely goodness and mercy shall follow thee all of thy days. Break them, and you will soon find yourself teetering on the brink of disaster. Abandon all hope ye whom embark down that dark road to ruin.

The height or length of a seahorse is measured from the top of its coronet to the tip of its extended tail, so those measurements are done when the tail is straight rather than curled.

What type of filtration are you planning on using for the 20-gallon hex tank?

Best of luck with your new seahorse setup!

Happy Trails!
Pete Giwojna

Dear hobbyist:

I agree that an upgrade from the 20-gallon hex would be a good idea, especially if you are new to seahorses and still learning the ropes with these amazing aquatic equines.

As you know, unless you will be keeping one of the miniature breeds of farm-raised seahorses, such as Hippocampus zosterae, H. breviceps, or H. tuberculatus, it’s best to start with the largest aquarium you can reasonably afford and maintain (the taller, the better). In general, a tank of at least 40 gallons (150 L) is preferable since that’s the size when one begins to see significant benefits in terms of the greater stability a larger volume of water can provide. An aquarium of 40-gallons or more will be more resistant to overcrowding and to rapid fluctuations in temperature, pH, and salinity than smaller setups. The larger the aquarium the larger the margin for error it offers the aquarist and the greater the benefits it provides in terms of stability.

It is equally desirable to select an aquarium at least 20-inches high when keeping the greater seahorses. They need the vertical swimming space to perform their complex mating ritual and successfully complete the egg transfer, which is accomplished while the pair is rising through the water column or drifting slowly downwards from the apex of their rise. If the aquarium is too shallow, eggs will be spilled during the transfer from the female to the male’s brood pouch, and mating becomes increasingly difficult or impossible below a certain minimum depth. A tall aquarium can also help protect the seahorses from depth-related health problems such as bloated pouch and certain forms of Gas Bubble Disease.

An external power filter is a valuable addition to any seahorse setup for several reasons. It will provide added water movement and circulation for your aquarium, as well as accommodating any mechanical or chemical filtration you may desire. A bewildering array of filtration options are available today, including a myriad of canisters and hang-on-the-back models, most of which will do the job reasonably well. Even the trusty old standbys, undergravel filters and air-operated sponge/foam filters, are still good choices for a standard seahorse setup.

If you are using 1-2 pounds of live rock per gallon as your primary biofilter, then a basic canister filter or hang-on-the-back filter is all you need to provide mechanical/chemical filtration and additional water movement. Otherwise, you’ll need to include a filter that can provide biological filtration. Undergravel filters and air-operated sponge filters can accomplish this and work well for some applications.

But wet/dry trickle filters are probably the most desirable units for the seahorse keeper if the aquarium has adequate space (behind or beneath it) to accommodate such a unit and the hobbyist can afford one. They are top-of-the-line units that feature a thin film of water trickling over filter media with an ultra-large surface area, thereby allowing maximum air-water contact. This provides excellent oxygenation with efficient offgassing, which is very important for seahorses. It helps keep dissolved oxygen levels high, CO2 low, and effectively prevents gas supersaturation, which can sometimes contribute to serious problems for our aquatic equines. As a added benefit, wet/dry trickle filters can also provide remarkable biological filtration, which can give you a real nice edge by further increasing your carrying capacity and boosting your margin for error accordingly.

The type or brand of supplemental filter you choose for your seahorse tank is not critical, but there are certain desirable features you want to look for in any filter that will be used for seahorses. For example, it should provide good surface agitation and water movement with adjustable flow. The intake tubes should reach all the way to the substrate (add extenders if they do not) and be screened off or otherwise shielded so they cannot "eat" a curious seahorse. The filter must provide efficient oxygenation and gas exchange and be able to accommodate mechanical and biological filtration media such as activated carbon and polyfilter pads. A prefilter is very desirable, as is a "waterfall" return (or a spray bar attachment, if you decide on a good canister filter instead).

There have been a few other threads on this forum from hobbyists who were just starting out with seahorses that you should find to be of interest. I’ve provided links to those discussions for you below, which discussed tanks and filtration, among other things, so please check them out. I think they will help answer many of your questions about setting up a suitable tank for seahorses:

Re: Guidance on Keeping Seahorses:
http://www.seahorse.com/option,com_simpleboard/Itemid,144/func,view/id,639/catid,2/

Re: New to seahorses and I have lots of questions!
http://www.seahorse.com/option,com_simpleboard/Itemid,144/func,view/id,152/catid,2/

Re: Tank set-up advice
http://www.seahorse.com/option,com_simpleboard/Itemid,144/func,view/id,715/catid,2/

Please let us know if you have any other questions that haven’t been covered in those previous discussions!

Best of luck with your new seahorse setup!

Happy Trails!
Pete Giwojna