new tank set up

thank you for the imput. i had thought about the black live sand and of course live rock for this tank and slowly adding assorted corals and plants. will the black sand affect the seahorses coloration or moods. I was hoping the black would accentuate the colors in the seahorses as well as help to bring out the colors in the corals. i am having the tank set up with a refugium and skimmer and uv filter as well. is there anything else i should consider when doing this tank as i want this to be a primarily seahorse tank. we were having so much fun with our 24 gal tank i decided to give myself just a bit more work, or maybe less, by moving to a 90 gal.

Dear ageber:

That’s a big thumbs up for your plans to upgrade to a 90-gallon setup for your seahorses! Including a refugium, plus a quality protein skimmer and an ultraviolet sterilizer should create an ideal dedicated system for seahorses.

Offhand, the only other improvements I could suggest would be to be sure to "debug" your live rock to eliminate unwanted hitchhikers if live rock will be a component of your new setup, and to keep your refugium well-planted with a lush bed of macroalgae. For best results, keep the algae bed eliminated continuously 24/7 in order to stabilize your aquarium parameters. If you’re concerned that the lighting in your refuge isn’t strong enough to sustain Caulerpa, then I would suggest that you try Chaetomorpha and assorted Gracilaria macroalgae instead. Those macros don’t require strong light to thrive; and would do very well under ordinary incandescent or fluorescent olds in a simple strip reflector or standard daylight fluorescent bulbs. I would situate a nice clump of Chaetomorpha and a good growth of Gracilaria in your sump directly under the lamp, and then keep them illuminated 24 hours a day right around the clock. That will accomplish several beneficial things: for one, keeping such limited lighting on continuously will help compensate for its relatively low output. Another big advantage is that it will encourage vigorous growth of the macroalgae and harvesting some of the macros regularly regularly will export large amounts of excess nutrients from your tank. Finally, operating the lighting in your sump around-the-clock will 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 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.

Best of luck with your plans for the new seahorse setup, ageber!

Happy Trails!
Pete Giwojna

Dear ageber:

Yes, sir, the porous interior of pre-cured live rock houses a considerable population of both aerobic nitrifying bacteria and anaerobic denitrifying bacteria, and this can provide the aquarium with some limited instant biological filtration ability and therefore help accelerate the cycling process. Live sand likewise contains both Nitrobacter and Nitrosomonas nitrifying bacteria, which helps speed up the nitrogen cycle by providing the necessary "seed" bacteria to kickstart the whole cycling process. But the use of live rock and live sand, or pre-aged saltwater, will not eliminate the need to cycle your aquarium entirely. You will still need to provide a source of ammonia to feed the beneficial bacteria and build up a sufficient population of the "good guys" in order to handle all the wastes produced by your seahorses, and you will have to monitor the aquarium closely while it cycles in order to determine when the process is complete.

Besides using live rock on live sand, there are a couple of other things you can do to further accelerate the cycling process. For instance, you can increase the aeration and the temperature in the aquarium while it is cycling. The beneficial nitrifying bacteria (Nitrosomonas and Nitrobacter sp.) that convert ammonia to nitrite and nitrite to nitrate are all aerobic or oxygen-loving microbes, so their population will increase faster if there is a high level of dissolved oxygen in the aquarium. Adding an airstone to provide better surface agitation and promote efficient aeration and oxygenation while your tank cycles should be helpful.

Secondly, I would raise the temperature in your aquarium to around 80°F while it cycles. Bacteria multiply faster at warmer temperatures, so raising the water temperature should help stimulate faster growth of the beneficial nitrifying bacteria as well. (Don’t forget to reduce the aquarium temperature back to normal once it’s finished cycling so that it’s optimal for your seahorses.)

There are a number of different ways to seed the tank with bacteria initially and feed it with ammonia so cycling can proceed. Two popular methods are the fishless cycle, which I recommend, and the use of hardy, inexpensive (i.e., expendable) fish to produce ammonia and cycle the aquarium. Often used for this method are marine damselfish or mollies, which can easily be converted to saltwater. Both are very hardy and generally survive the cycling process, but I find this method to be needlessly hard on the fish and exposing them to the toxic ammonia and nitrite produced during cycling certainly causes them stress. Damselfish are far too aggressive and territorial to leave in the aquarium afterwards as tankmates for seahorses. Mollies are a possibility, but they really look out of place in a saltwater setup.

So all things considered, I recommend cycling your tank without fish, just as Katja suggested. It’s really very easy. To use the fishless cycle, you need to add something else that will increase the ammonia level so the nitrifying bacteria can build up. I like to use a piece of cocktail shrimp (regular uncooked eating shrimp from the grocery store) and leave this in the tank to decay during the whole cycle. The decaying shrimp produces plenty of ammonia to kick-start the cycling process.

After about 3 days after you add the shrimp, you will notice a spike in ammonia levels until the Nitrosomonas bacteria build up enough to break down the ammonia. When that happens, you will notice the ammonia levels rapidly dropping. (If for some reason your ammonia does not hit the top of the charts initially, you may want to add another piece of shrimp.)

The byproduct of ammonia is nitrite, and during this stage of the cycling process, as the ammonia falls, you will have a corresponding increase in nitrites until the population of Nitrobacter bacteria builds up. Nitrite levels will then fall as the Nitrobacter convert the nitrite to nitrate.

It is important to use your test kits every day or two when cycling your tank to monitor the progress of the process. As described above, normally at first you will see a rapid rise in ammonia levels with no detectable nitrite or nitrate. Then, as Nitrosomonas bacteria begin converting ammonia to nitrite, the ammonia levels will fall and nitrite readings will steadily rise. Nitrite levels will peak as the ammonia drops to zero. Next, Nitrobacter will begin converting the nitrite to nitrate, and your nitrite readings will fall as the level of nitrate rises. Finally, after the nitrites also read zero, you are ready to stock your tank. At this point, your ammonia and nitrite levels should both be zero, nitrates will be building up, and algae will usually begin to grow. This will tell you that your biofilter is active and functioning properly, and that you can now safely begin stocking the tank. It generally takes about 3-6 weeks to cycle a tank this way from scratch. But if you’re using live rock and live sand, along with pre-mixed, aged saltwater, you can expect a much faster cycle. Just monitor your tank as suggested above and you’ll know when it is safe to transfer their seahorses to the 90-gallon aquarium.

Best of luck with your aquarium upgrade, ageber!

Happy Trails!
Pete Giwojna