Dear saltfreak:
Yes, sir, I have to agree with you — it sounds like you’ve created a veritable seahorse paradise! Plenty of live rock and live sand, outstanding height, efficient filtration including a good protein skimmer and a sump, lots of macroalgae, a refugium, and a tank teeming with assorted ‘pods — that’s the sort of complex environment with a variety of microhabitats that seahorses need to thrive. That would make an ideal biotype for Mustangs and Sunburst (Hippocampus erectus) or most any other tropical seahorses. A tank that’s 36 inches tall should really minimize any problems with gas bubble syndrome. Well done!
It would be hard to improve on a superb setup like that but I do have one or two minor suggestions to offer.
First of all, I suggest keeping the macroalgae in your refugium and/or sump illuminated around-the-clock or on a reverse photoperiod to the main tank in order to help 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 in essence 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 maintaining 24-hour illumination in your refuge and/or sump. 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.
Secondly, I would suggest adjusting the lighting on the main tank so that provides your seahorses with a simulated dusk and dawn, as described below. Personally, I like 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).
I would also consider installing an ultraviolet sterilizer in your sump. 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, 2003a).
The primary benefits UV sterilization provides, however, are disease reduction and the reduction 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, 2003a). Seahorses are prone to a number of serious bacterial problems such as Vibriosis, and a properly installed and maintained UV sterilizer can be invaluable in reducing the incidence and spread of such infections. When properly used, UV sterilization can reduce microbial levels in the aquarium to the low levels normally found in the wild or below (Fenner, 2003a).
For best results, the UV sterilizer must be properly sized, operated, and maintained. In order to provide a good kill rate per pass, the effective dwell time (the length of time the water is exposed to UV radiation while passing through the sterilizer) should be maintained at or above roughly twenty gallons per hour flow per watt of UV (Fenner, 2003a). This sounds complicated, but selecting the right sterilizer for your needs is actually very easy. Every manufacturer provides guidelines to help the hobbyist choose a unit and a pump that provide the proper wattage, flow rate and exposure time for any given application.
To assure efficient transmission of the proper wavelengths, sleeves (i.e., the quartz jacket that shields the lamp) must be kept clean and UV bulbs must be replaced at regular intervals. Equally important, the aquarium water should be filtered before it passes through the sterilizer. For maximum efficiency, make the UV sterilizer the final component of an in-line filtration system, so that the water has already passed through your mechanical, biological and chemical filtration media before it flows through the sterilizer (Fenner, 2003a). Do not operate your UV sterilizer during the break-in period when a new aquarium is being cycled and the biological filtration is becoming established. It is counterproductive to reduce microbe levels and nutrient levels when the aquarium is cycling.
Ultraviolet sterilizers are not necessary for maintaining seahorses, but nowadays I would not attempt to keep wild-caught seahorses without one. Hardy, disease-resistant farmed-raised seahorses can do just fine without them, and reefers often frown on UV because it reduces the population of microscopic planktonic organisms filter-feeding invertebrates require. But in my opinion a UV sterilizer makes a very useful addition to the filtration system of the average seahorse setup. The fish farms and aquaculture facilities that raise captive-bred seahorses employ UV radiation in their nurseries and grow-out tanks, and there is no reason the home hobbyist should not take advantage of this technology as well.
Best of luck making a few minor adjustments to your outstanding seahorse system, saltfreak! Your seahorses showed flourish in a tank like yours and will definitely enjoy grazing on the abundant pod population between meals.
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.
