Re filtration

Dear Alirich:

Okay, a corner tank of 45 gallons (~180 L) that’s 24 inches tall can certainly make a fine seahorse habitat. It has the superior height that is so important for seahorses as well as good water volume to provide stability, a comfortable margin for error, and plenty of room for the seahorses to explore.

But unless the corner tank is equipped with its own built in filtration system behind a false back, the unusual design of the tank can make it difficult to provide it with efficient filtration, and, in that case, there are not many good options to consider.

For example, good old reliable, outdated, undergravel filters can still be a good option for filtering a seahorse tank, but I doubt you will be able to find a set of undergravel filters designed for corner tank, which means you’ll probably have to rule them out, Alirich. The problem is, of course, that your corner tank has a triangular footprint, and undergravel filters are manufactured to fit standard rectangular aquariums primarily. Needless to say, you cannot make a rectangle fit inside a triangle neatly, so a rectangular undergravel filter would leave large areas on the bottom of the corner tank unfiltered, which would make inefficient and could lead to problems in the long run.

Another option would be to use a good hang-on-the-back external power filter that can provide mechanical, chemical, and biological filtration, preferably supplemented with a quality hang-on-the-back protein skimmer rated for tank of at least 50 gallons (~200 L). But that would require 4-6 inches of working space behind the aquarium, which would defeat the whole purpose of having a corner unit, since it would no longer fit snugly in the 90° angled niche it was supposed to occupy.

A sump would be a good option but it might be challenging to equip your corner tank with a sump if it was not designed for that purpose. If the corner aquarium is not "reef ready" (i.e., pre-drilled so that it could be easily plumbed into a sump) then you would have to either have the tank drilled or install an overflow that could be connected to a sump, which could become a complex DIY project for a home hobbyist.

Even if you could manage the plumbing, the sump would have to be pretty small in order to fit beneath a corner tank, Alirich. It’s the same problem of trying to fit a rectangular sump into the triangular footprint of a corner tank; in order to do so, the rectangular tank must be quite small, and you need it to be large enough to accommodate a good in-sump protein skimmer as well is a good biofilter (perhaps a wet/dry trickle filter or a fluidized bed filter that can provide efficient biological filtration). So a sump could be an option for you, Alirich, but it would require a lot of modification and ingenuity to make it work well…

Perhaps your best option might be to use a natural filtration system featuring a well-managed deep live sand bed (DLSB) about 4 inches deep and enough live rock to provide the tank with both efficient nitrification ability and denitrification ability, Alirich. With the live sand and live rock providing all the necessary biological filtration, you would simply need to equip the tank with one or more powerheads to provide adequate water flow, good surface agitation, and efficient water circulation.

Just make sure 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. Basically, 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.

When that’s not possible, you may need to take more elaborate measures in order to screen off the intake from the pump are powerhead to make it safe for the seahorses, Alirich.

For example, here’s how to proceed when using the Hydor Koralia powerheads, which are relatively safe compared to other types of powerheads. 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 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 coraline 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 definetly 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.

Best of luck equipping your corner tank with the perfect filtration system for your needs and interests, Alirich.

Respectfully,
Pete Giwojna, Ocean Rider Tech Support