thinking of converting my 120 t0 salt

Dear Mom:

It may not be as difficult to convert your 120-gallon cichlid tank for seahorses as you imagine, and an aquarium of that size would offer great stability and provide the superior height that is so important for a good seahorses.

For example, your existing light fixture should be more than adequate for seahorses, and your Aquaclear 110s and Fluval 250 will work very well for providing the biological filtration and water movement you want for a seahorse tank. It would be a good idea to supplement them with a good hang-on-the back protein skimmer, but that’s not a big deal and is an optional piece of equipment for the aquarium.

And you may not need to replace your rockwork at all. If you are using lace rock or grotto rock for your cichlids, that will work in saltwater just as well as it did in freshwater. Other types of rock, however, are best replaced with live rock since they may contain minerals that could leach out in the saltwater to the detriment of the fish and invertebrates. Even in that case, replacing the rock bottom with live rock may not be as expensive as you think, since you will not be using the live rock as your primary form of biofiltration, and can therefore get by with a lot less of it. You will just need to add sufficient live rock to provide stability and some denitrification ability.

Otherwise, you just need to add a shallow layer of live sand for the substrate and you should be all set. A thin layer of live sand, preferably black, is the ideal substrate for a SHOWLR tank. It is bioactive, aesthetically pleasing, and is a fine-grained sand well suited for the various snails that form an essential part of the cleanup crew for a seahorse tank. I find the dark color shows off my seahorses and macroalgae to great effect and enhances the appearance of tank in general.

The depth of a shallow sand bed like this is a crucial factor. Too deep, and you risk anaerobic dead spots where deadly hydrogen sulfide gas can form. Too shallow, and there will be less surface area to support beneficial nitrifying bacteria and Nassarius snails and other beneficial burrowers may feel vulnerable and exposed. A bed of live sand 3/4-inch to 1-inch deep is just right for the main tank. A properly layered Deep Live Sand Bed (DLSB) 3-6 inches deep with a full complement of sand shifters also works well with seahorses, but is best confined to a sump rather than the display tank due to the seahorse’s heavy waste production.

The type of sand I usually prefer for this is Nature’s Ocean Bio-Activ Live Aragonite Black Beach sand. A thin layer of the sand should make the ideal substrate for your aquarium, and you can order it online from the following site:

http://www.naturesocean.com/live_sand.htm

Otherwise, either the Arag-Alive Indo-Pacific Black Sand by CaribSea or else the CaribSea Tropical Isle Tahitian Moon Black Sand would be good alternatives. You can obtain them online from Premium Aquatics and a number of other sources, and either of them should also work well for the substrate in a seahorse tank.

You will also need to add some suitable hitching posts and holdfasts for the seahorses to perch on, and this is what I normally advise hobbyists in that regard, mom:

Aquarium Decor

When aquascaping a seahorse tank, the idea is to create a complex, natural environment for the seahorses with lots of shelter, well-shaded retreats, and convenient hitching posts. Seahorses prefer a fairly elaborate setup with lots of microhabitats that offers them plenty of cover and sight barriers so that they don’t feel vulnerable and exposed.

The plants and decorations can be real or synthetic, or a mixture of both. You can combine live plants with synthetic plants and live corals with artificial corals as you please in order to provide colorful, natural surroundings for your seahorses and create an aesthetically pleasing aquascape that will make your seahorses feel right at home.

A certain amount of complexity is desirable in a seahorse setup. For example, a tank with too few attachment sites and hitching posts is a stressful environment for seahorses, as is a sparsely decorated aquarium that leaves these secretive animals feeling vulnerable and exposed. Such sterile environments are commonplace when seahorses are being maintained under laboratory conditions. A Spartan setup facilitates feeding, water changes and maintenance, in general, but it can adversely affect the behavior of the inhabitants and may even prevent captive seahorses from breeding.

Hippocampus relies on camouflage and remaining hidden for its very survival. Seahorses can thus become distressed and agitated if their tank is too barren to provide adequate cover. This is particularly true during courtship and mating when the increased activity level and heightened coloration make them highly conspicuous and vulnerable, and breeding may be severely inhibited under these conditions.

A recent research project that studied the behavior of captive Cape seahorses (Hippocampus capensis) recently confirmed the need for a certain level of complexity in any setup for seahorses (Topps, 1999). The study found that seahorses display more "natural" behavior when they are provided with an elaborate, structured environment that includes a number of different microhabitats (Topps, 1999). These findings are another indication that a sparse setup with inadequate shelter can inhibit the behavior of captive seahorses.

As we’ve been discussing, your seahorse setup should therefore include plenty of hiding places and sight barriers such as live rock, real or artificial branching corals, and marine plants. It should be well planted and have lots of convenient hitching posts. This is what I usually advise hobbyists with regard to hitching posts:

Hitching Posts

When it comes to hitching posts and decorations, seahorses in general tend to prefer perches that are bigger in diameter over skinnier ones that are a bit more difficult to get a good grip on with their tails, but other than that, it’s very difficult to predict what they’ll go for. I have noticed that tree sponges and tube sponges — both the real thing (which are difficult to keep healthy) and the lifelike artificial versions (a better choice for most tanks) — almost always seem to be particular favorites. Very often such sponges are bright red or yellow or brilliant orange in coloration, but I think it is the structure and texture of the sponges that attracts the seahorses more than the color.

Seahorses often tend to gravitate towards gorgonians, and the big purple gorgonians that are large in diameter are also usually very popular with seahorses. Otherwise, they seem to like genuine corals and synthetic corals about equally well, and the brightly colored formations (orange, red, or vivid yellow) usually produce better results than plain white corals.

Hitching posts for your seahorses can thus be either live or artificial marine sea grasses, algae and corals. If you decide to try an assortment of colorful artificial corals, seahorses often prefer red or orange pieces. Many hobbyists report good results using artificial finger sponges, staghorn coral, octopus coral and pillar coral in the appropriate colors to keep their seahorses looking their brightest. They look entirely natural and lifelike, with lots of branching projections that make great hitching posts for seahorses. Oh, and the cup coral often makes a great ready-made feeding station! Living Color and the Signature Coral Corporation are the best sources for artificial corals, in my opinion.

For lifelike artificial hitching posts, you can’t beat the colorful, realistic Living Color corals (http://www.livingcolor.com/coral.cfm). They offer an assortment of harp gorgonians, seafans, sea whips, and sea rods in various colors that all make outstanding hitching posts for seahorses. They come in a variety of colors (red, burnt orange, yellow-gold, and purple) and are very realistic in shape, color, and texture. These types of gorgonia normally grow attached to rocky reefs in the ocean, so they would look perfectly natural amidst your live rock.

The following Living Color items all make terrific colorful hitching posts for seahorses:

Sea Fans — item number 385 RD, PL, GD.

Harp Gorgonian — item number 483 GD or RD

Sea Rod — item number 485 BTOR or RD or PL or GD.

Sea Whip — item number 108 BTOR or RD or PL or GD.

I also like the following the tube sponges offered by Living Color:

Tube Sponge — item number 187 DPK.

And the Velvet Stone Coral they offer makes a good natural-looking feeding station for seahorses:

Velvet Stone Coral — item number 360 DPK

Sea Garden synthetic aquarium plants also make good hitching posts for seahorses. The Sea Garden saltwater series of "Fancy Plants" are very realistic, completely safe for saltwater, and very easy to maintain. Just rinse them under warm running water before installation and periodically thereafter for cleaning. There’s a very nice selection of them available and seahorses can’t seem to tell the difference between them and the real thing.

For background decorations in a tall tank, I especially like the SeaGarden synthetic Sargassum plants because Hippocampus erectus is often associated with Sargassum in the wild and is famous for its rafting ability on mats of these plants. So it’s a natural biotype for erectus, and of course the Sargassum grows nice and tall, which is what we want for aquascaping the extra-tall tanks that are best suited for seahorses. I like to obtain one or more of the Large, Tall, and Extra Large examples of both the Sargassum fluitans (reddish brown in color) and the Sargassum platycarpum (green in coloration) and arrange them together across the back of the aquarium. They range in size from 12 to 24 inches in height, so if you group the tallest of the plants together, they should effectively conceal the filtration system and enhance the beauty of the aquarium, creating a colorful natural background with shades of green, brown, and red. They sway in the current just like the real plants and are very easy to clean and maintain. Just rinse them well under warm water when they need cleaning.

Before you put them in your aquarium, however, I recommend rinsing the Fancy Plants thoroughly under warm water and then soaking them in a bucket of clean tap water for several days, changing the water every day throughout this period to keep it clean and fresh. After the artificial plants have soaked for several days in this manner, you can give them another good rinse under warm water and then arrange them in your aquarium.

The SeaGarden Fancy Plants I mentioned above are available online from Drs. Foster and Smith at the following URL:

http://www.drsfostersmith.com/Product/Prod_Display.cfm?pcatid=9121&N=2004+113149

Macroalgae — Living Hitching Posts

For live hitching posts, I prefer decorative marine plants or macroalgae in a variety of shapes and colors and color — reds, golds, and yellows in addition to green varieties, some tall and feather, some short and bushy — to provide them with natural hitching posts and shelter. I like to start with a mixture of red and gold Gracilaria (Ogo) and artfully arrange them around a lush bed of assorted bright green Caulerpa. Any of the plumed (feathery) or long-bladed Caulerpa would be ideal for this, such as Caulerpa sertularioides, C. mexicana, C. ashmedii, C. serrulata or C. prolifera. But they may not be the best choice for tall tanks since none of these species will grow more than about 4-6 inches in height at the most.

Be sure to thin out the fast-growing Caulerpa regularly; when you remove the excess fronds, you’re exporting phosphates, nitrates and other nutrients from the tank, thereby helping to maintain good water quality, and thinning out the runners helps keep it from going sexual.

When thinning out Caulerpa and other macroalgae, take care not to actually cut it. Remember, you’re not pruning hedges or trimming trees — the idea is to carefully pull up and remove continuous, unbroken fronds. Simply thin out the colony of excess strands, gently plucking up convenient fronds that can be readily removed intact. A little breakage is fine, but cutting or breaking too many strands will result in leaching undesirable substances into the aquarium water as the Caulerpa’s lifeblood drains away. Too much cutting or breaking can thus sap the colony’s strength and cause die offs or trigger the dreaded vegetative events that judiciously thinning out the colony otherwise prevents.

If find it difficult to obtain Caulerpa (it’s illegal in some coastal areas) or you’re simply concerned about your ability to maintain and control of Caulerpa properly, just use a different forms of macroalgae that grows less rapidly instead and you can get the same sort of benefits at relatively little risk. In that case, some of the other macroalge you may wish to consider are Gracilaria, Ulva, Chaetomorpha, and Chlorodesmis. Hawaiian Ogo (Gracilaria sp.) are bushy red-to-brown macros that do well under low light levels. Sea Lettuce (Ulva sp.) are deep green sheets of algae that do best under a little stronger lighting. Maiden’s Hair (Chlorodesmis sp.) are bright green tufts or clumps of very fine-bladed algal mats to grow attached to small rocks. All of these types of macroalgae are much less prolific and slower growing than Caulerpa. However, like all macroalgae, they should still be harvested periodically in order to export the excess nutrients they have consumed.

Aside from red and brown Gracilaria and the bright green Ulva and Maiden’s Hair, some seahorse keepers also like the Chaetomorpha turf algae or spaghetti algae, as it is also known. It can best be described as looking like the clumps of the colorful plastic grass we use to fill Easter baskets. Good on seven It is popular because it is slow growing and doesn’t require the kind of pruning that Caulerpa needs, and because it comes loaded with microfauna: miniature feather dusters, copepods and amphipods, tiny snails and micro stars. In short, Chaetomorpha is another interesting marine plant that can add some extra variety to a lush bed of macroalgae.

If you are looking for colorful macroalgae that goes well with live rock and will provide good hitching posts for seahorses, then I think you might like the "red-on-rock" algae species offered by Inland Aquatics. They are more colorful and won’t overgrow or overwhelm your tank.

Maiden’s hair algae and sea lettuce (Ulva spp.) are bright green species of macroalgae that normally grow attached to rocks and are typically sold that way for aquarium use. They could also be placed on mid-your live rock where they would receive bright light.

If you are looking for marine plants to maintain in a sandy area of your tank, many species of Caulerpa, Merman’s shaving brushes (Penicillus spp), Udotea "sea fans," and Halimeda sea cactus are available, all of which are just anchored in the sandy bottom and will put out rhizoids or holdfasts to keep himself in place. Other species of Halimeda are available that sprout from live rock instead, so that’s another option if you prefer.

But the Halimeda sea cactus, Penicillus shaving brushes, and Udotea sea fans are all calcareous macros that require high levels of calcium in order to thrive. To maintain them successfully, you will need to monitor the calcium levels, total alkalinity, and carbonate hardness of your seahorse setup, provide occasional supplements of calcium or Kalkwasser, and maintain the aquarium more like a reef tank than an ordinary saltwater system.

Some macroalgae are rootless and do not anchor in place. This is true of the Chaetomorpha turf algae or spaghetti algae, for instance. It grows in tangled clumps that look like nothing more than the colorful green Easter grass we use in our Easter baskets as betting for the jellybeans, marshmallow chicks, and chocolate bunnies. Chaetomorpha is therefore not very aesthetic looking in your main tank, but you can’t beat it for use in refugia or algal filters because hordes of copepods, amphipods, and other microfauna love to shelter, feed, and breed in the tangled masses of the spaghetti algae.

Like the Chaetomorpha, different types of Gracilaria or Ogo are often cultured by tumbling them so that they are always in motion, exposing different areas of the plant masses to the sunlight and assuring that clean water circulates through them continually. Several different types of Gracilaria (red, brown, green) are available and are typically sold in clumps by the bag or the pound. They don’t have roots as such, of course, but if you wedge them in crevices in your live rock or anchor them in place with a small rock or piece of coral rubble, they will attach to a hard substrate and grow well under favorable circumstances. Again, like the Chaetomorpha, these balls or clumps of Gracilaria/Ogo are ideal for culturing copepods and amphipods in your sump or refugium, but they will also look nice in your main tank once they take hold.

When it comes to the live macroalgae (living marine plants), you can get various species of Ogo (Gracilaria) from Ocean Rider, but for more color and variety, there are a number of other places to order suitable live plants online.

For example, Inland Aquatics has perhaps the best selection and variety of macroalgae available:

http://www.inlandaquatics.com

Aquacon is another good source for cultured macroalgae:

Click here: Marine Plants for Saltwater aquariums
http://www.aquacon.com/vip.html

Seahorses also like live rock, particularly colorful pieces that are heavily overgrown with pinkish or purplish coralline algae. Aside from looking pretty, live rock also provides additional biological filtration (both nitrification and denitrification) for the aquarium and provides shelter and sight barriers that make the seahorses feel secure.

In short, special attention to the hitching posts you select when decorating your seahorse tank. Strive for bright reds, oranges, and yellows in anything your seahorses may adopt as a holdfast. These aquatic equines — especially the stallions — will often choose one particular hitching post as their home base and spend much of there time perched right there (think of your Dad hunkered down in his favorite easy chair in the den). Once they adopt a favorite base of operations like this, they will often proceed to change coloration to match their preferred resting spot. So you want to encourage them to adopt one of the more vivid pieces as a favorite holdfast whenever possible.

In short, I think you could transform your cichlid tank into an excellent seahorse tank without a great deal of effort and expense, mom. If you contact me off list ([email protected]), I will be happy to send you a lot of additional information explaining how to optimize your 120-gallon aquarium for seahorses.

Best wishes with all your fishes!

Happy Trails!
Pete Giwojna