Dear Katie:
You are correct — a tall aquarium is very desirable for the larger breeds of seahorses in order to allow them enough room to mate comfortably and to protect them from depth-related conditions such as gas bubble syndrome (GBS). So if you will be keeping any of the greater seahorses, an aquarium that is 20 inches tall or higher is highly recommended.
However, when keeping small seahorses or the miniature breeds like Pixies (H. zosterae), then an aquarium 20 inches high or better is no longer a prerequisite. The usual rule of thumb is that seahorses require vertical swimming space equivalent to about 2-3 times their total length in order to complete the copulatory rise and mate comfortably. With miniature seahorses like Pixies that never grow larger than even 2 inches in total length, or small species like Zulu-lulus (H. capensis) that rarely exceed a total length of 3-4 inches, all that extra height is no longer strictly necessary. In fact, Pixies or dwarf seahorses (H. zosterae) do best in much smaller aquaria (2-10 gallons) where it is easier to maintain an adequate feeding density of the newly hatched brine shrimp (Artemia nauplii) that are their staple diet.
Yes, Zulus (Hippocampus capensis) are a good choice for a beginner with a modest aquarium providing you can keep the temperature cool enough for these temperate seahorses. That usually requires an aquarium chiller for best results.
Fortunately, there are some very affordable mini aquarium chillers that could easily be mounted on your 12-gallon setup. For example, the CoolWorks Ice Probe and Microchiller units are ideal for small tanks (10-15 gallons) and will drop the water temperature up to 6-8°F below the ambient room temperature:
Click here: CoolWorks Ice Probe with Power Supply – Marine Depot – Marine and Reef Aquarium Super Store
<http://www.marinedepot.com/md_viewItem.asp?idProduct=CW1111>
Click here: CoolWorks Microchiller – Marine Depot – Marine and Reef Aquarium Super Store
<http://www.marinedepot.com/md_viewItem.asp?idproduct=CW1131>
If all you have available is a small aquarium and an aquarium chiller isn’t in your plans for the immediate future, Katie, then you might be better off considering downsizing and going with Pixies instead. I will send you a lot of additional information on Hippocampus zosterae that discusses the best setups and aquarium options for these miniature marvels off list, as we have previously discussed.
In the meantime, if you haven’t seen it already, please check out the following thread which discusses keeping Pixies (H. zosterae) or Zulu-lulus (H. capensis) in a 12 gallon nano cube:
Click here: Seahorse.com – Seahorse, Sea Life, Marine Life, Aquafarm Sales, Feeds and Accessories – Re:Recommendation for 12gl nano cube
http://www.seahorse.com/option,com_simpleboard/Itemid,144/func,view/id,1638/catid,2/
Best of luck with your plans for a miniature seahorses exhibit, Katie!
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.
