Dear Sean:
Sounds real good! That’s an excellent lighting system — very much the same as I prefer for my seahorse tanks — so once you get your photoperiod tweaked properly, that may help.
For best results, monitor your calcium levels and use a calcium supplement such as Kalkwasser to bring it up to the desired level, if necessary. And I would also keep tabs on the dissolved oxygen levels in your seahorse tank, as discussed below:
Dissolved Oxygen (02): Optimum level = 6 – 7 ppm
High levels of dissolved oxygen are vital to the well being of both fish and invertebrates. The key to maintaining high O2 levels in the aquarium is good circulation combined with surface agitation (Webber, 2004). Wet/dry trickle filters and protein skimmers facilitate efficient gas exchange and oxygenation. It is important for the hobbyist to monitor the dissolved oxygen levels in the aquarium because a drop in O2 levels is often an early indicator of impending trouble — a precursor of problems ahead. A drop in O2 levels will tip off the alert aquarist and allow corrective measures to be taken, nipping the problem in the bud before it adversely affects his seahorses. Low levels of dissolved oxygen cause lethargy and respiratory distress, and can contribute to a loss of appetite or even trigger a hunger strike, in addition to affecting hormone levels and having an adverse impact on a gestating seahorse.
For these reasons, I recommend that you use a test kit for measuring the dissolved oxygen in your seahorse setup. The reason for this is that a drop in the level of dissolved oxygen is a great early warning indicator that something is amiss in the aquarium, and can thus predict potential problems (and allow you to take corrective measures) BEFORE they become full-fledged disasters. For example, a drop in O2 levels could be an early indicator of overcrowding — a signal that your system has reached its carrying capacity. Or it may merely signal a rise in the water temperature due to a summertime heat wave or indicate that the tank is overdue for a water change and/or a thorough cleaning to remove excess organics and accumulated detritus. Or it could be telling you that your tank is under circulated and you need to increase the surface agitation and water movement. On the other hand, it can also alert you to a potential gas supersaturation event, which can sometimes happen if a faulty intake or leak allows air to be entrained in a pump.
The point is that checking the O2 levels in your aquarium can alert you to impending problems and allow you to do something about them before they have dire consequences. A drop in O2 levels is often the first sign of a water quality problem and it can tip off the alert aquarist that trouble is brewing before his seahorses are gasping for air in obvious respiratory distress. Checking the dissolved oxygen levels regularly is the next best thing to continuously monitoring the Oxidation-Reduction Potential (ORP) or redox of the water, which is a luxury few hobbyists can afford.
As you know, seahorses are more vulnerable to low O2/high CO2 levels than most fishes because of their primitive gills. Unlike most teleost (bony) fishes, which have their gills arranged in sheaves like the pages of a book, seahorses have rudimentary gill arches with small powder-puff type gill filaments. Seahorses are said to have "tufted" gills because they appear to be hemispherical clumps of tissue on stems. Their unique, lobed gill filaments (lophobranchs) are arranged in grape-like clusters and have fewer lamellae than other teleost fishes.
Methods for measuring dissolved oxygen in the aquarium can be as simple or as sophisticated as you desire, ranging from basic test kits under $10 to electronic probes costing hundreds of dollars. Fortunately, the humble seahorse keeper doesn’t require anything too fancy along those lines, and the basic O2 test kits will do nicely for our purposes.
For instance, the Tetra Oxygen Test Kit (TetraTest 02) is a good liquid reagent test kit for fresh or saltwater with simple color scales for comparing readings that tests for 02 in the range of 2-14 PPM. It will cost you between $8.50 to $14 depending on where you shop and should be available at any well-stocked LFS. Salifert also makes a nice 02 Test Kit (their 02 Profi-Test) that will run you about $20.
Either of those test kits fit the bill very well and are worthwhile investments for the seahorse keeper.
Best of luck with your seahorses, sir! Here’s hoping they get serious about mating again very soon.
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.
