Reply To: Powerheads

Dear Eric:

Yes, sir, an aquarium that is 24 inches tall and 4 feet long with a substantial sump can make an exceptional habitat for seahorses.

I recommend Hydor Koralia Powerheads for use in a seahorse tank.

As you know, you do need 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. In general, 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.

The Koralia powerheads are relatively safe compared to other types of powerheads, in that regard, Eric, which is one reason I like the Hydor Koralia Powerheads for use in seahorse tanks. 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:

<Open quote>
“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 coralline 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 definitely hitch on the Koralia (and I have the nano) The pump still works great and nothing can get in it.”
<Close quote>

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.

Also, Eric, Koralias have a sort of “flow focuser” that you can snap on the front of the egg to help direct the flow. I would recommend keeping this collar on, since it will act as an additional barrier if a seahorse was to try and hitch to the very front of the egg, and because it will increase the strength of the water flow from the
Koralia by concentrating it in a smaller stream that is therefore considerably stronger than otherwise.

And I like the idea of setting up a large refugium in your sump that’s connected to your main tank and filled with plenty of Chaetomorpha spaghetti algae and/or Ogo macroalge, which will provide the perfect habitat for Gammarus amphipods, copepods, feeder shrimp, and other live foods species in a refugium. That way the Gammarus and copepods and other small crustaceans can build up a very large population well they are safely protected within the refuge, and some of them will be released into the seahorse tank to provide tasty treats for the ponies.

A refugium is simply a self-contained protected area, isolated from the main tank but sharing the same water supply, which provides many of the same benefits as a sump. A refugium can help newly added fish or invertebrates easily acclimate to a new tank. It can provide a safe haven for injured fish or corals to regenerate damaged tissue without the need for a separate quarantine tank. But perhaps its main benefit for the seahorse keeper is provide a protected area where macroalgae can be grown and small live prey items (copepods, amphipods, Caprellids, etc.) that will eventually become a food source for the inhabitants of the main portion of the tank can be cultured safely, allowing their population to build up undisturbed.

For instance, Charles Delbeek likes to use glass shrimp and cleaner shrimp that are too large to be eaten in the refugium for his seahorse tank, where the regular reproduction of these hermaphroditic crustaceans will provide a continuous supply of nutritious nauplii for his ponies: “There is a method that can be used to offer an occasional supply of live food for your sea horses. By setting up a separate system housing several species of shrimp such as the common cleaner shrimp (Lysmata amboinensis), peppermint shrimp (Lysmata amboinensis), or Rhynchocinetes uritai or R. durbanensis, you can get a fairly regular supply of live shrimp larvae. These species are best to use since they can live in large groups and spawn on a regular basis. Such a system is commonly called a refugium. A refugium is a small (10-20 gallon) aquarium that contains live sand, live rock and/or macroalgae such as Caulerpa or Gracilaria. It is plumbed such that water from your main system is pumped to the refugium and then returns via an overflow to the main tank. Some of the pods and larval crustaceans will then be carried from the refugium into the sea horse tank in the water that overflows from the refuge. For this type of arrangement to work, the refugium must be slightly higher than the main tank. Shrimp are added to the refugium and within a few months they should start spawning and hatching eggs every few weeks. The larvae are then carried back to the main tank by the overflow, where they become a food source for your sea horses. Of course, other life will also thrive in the refugium and it is not unusual for copepods, Mysis and crab larvae to also be produced on a regular basis. The key to the refugium is to keep predators out of the system so that the smaller micro-crustacean population can thrive. You would need a fairly large and productive refugium to produce enough food to maintain even a pair of sea horses, so at best, a typical refugium can provide a nice source of supplemental live food; the basic daily diet still needs to be provided by you in the form of the frozen foods mentioned above.” (Delbeek, November 2001, “Horse Forum,” FAMA magazine)

Best of luck finding the perfect powerheads for your new seahorse setup and the perfect combination of feeder shrimp and pods for your refugium, Eric! It

Respectfully,
Pete Giwojna, Ocean Rider Tech Support