Keeping Seahorses: Three Keys to Success

By: | Date: 09/12/2005 | 27 Comments |

Please note: If you’ve never kept a saltwater aquarium, I strongly advise you become familiar with marine aquarium keeping before attempting to keep seahorses. Seahorses are a sensitive fish that require an experienced, or at least dedicated hand. For those just starting out in marine aquariums, I can’t recommend Marine Reef Aquarium Handbook by Dr. Robert Goldstein enough. It has great beginner information but touches on many in-depth concepts.

Tigertail Seahorse in home aquarium

Tigertail Seahorse in home aquarium

It wasn’t long ago that seahorses were considered “impossible” to keep in captivity. Many believed they were only suitable for those with massive resources such as public aquariums. If the home aquarist were to attempt to keep seahorses, they needed to live near the ocean so they could collect food on a daily basis, and even then, they only met limited success.

Fortunately, times have changed. Advancements in modern marine keeping as well as a better understanding of seahorses and their requirements means anyone with the dedication and willingness to learn can keep seahorses. What we have learned is that seahorses have their own special requirements, and if those needs are met, they can be kept healthy and happy in the home aquarium. The secret to keeping seahorses is the right environment, proper feeding, and getting healthy specimens. We will cover how to do all three in this article.


Seahorses aren’t your typical reef fish. Well, they’re not your typical anything! They require a specialized environment to thrive in captivity. Rarely do they do well in your normal reef aquarium.

A seahorse aquarium needs to be set up differently than most reef aquariums. One common misconception is that they need to be kept in slow moving water. It is a common misconception still heard today.  Modern seahorse keeping, and observing them in the wild has revealed they need a faster flow rate. You’ll want to shoot for a flow rate of  10x-20x/hr. Some experienced aquarist go higher. What exact is the flow rate? It’s the number of times per hour the entire volume of water “turns over” or moves through the pumps. For example, if you have a 30 gallon aquarium, and you want to have a 10x turnover, you would take 30 and multiply by 10. This would give you 300 gallons per hour turn over, and thus, the flow rate you are looking to achieve is 300gph. This can be through one 300gph pump, or through multiple smaller pumps, such as three 100 gph pumps or six  50 gph pumps. It is a good idea to have areas of high flow, as well as areas that are sheltered from the flow with a few hitching posts, so the seahorse can rest if need be. And because seahorses are slow swimmers, it’s imperative that any intakes and overflows be covered to prevent any risk of the seahorse being caught in an intake.

Temperature is also an important concern for seahorses. Seahorses seem to lack the ability to fight off certain bacterial infections, so hobbyists have found the best way to help keep bacteria from proliferating is a clean tank and lower temperatures. Bacterial multiplies rapidly at reef tank temperatures, but dropping the temperature a few degrees to the low 70s for tropical species has made a big difference over the past few years for many seahorse keepers and its now recommended to keep most species under 74 degrees.

Tankmates need to be slow. Seahorses are not very fast at catching food; some will stare at a piece for a good ten minutes before deciding it is edible. Highly aggressive, fast tankmates will usually end up stealing all the food. In addition, gregarious, fast moving fish tend to make seahorses nervous and can cause undue stress, which can lead to illness. Keep the tankmates slow and small, and your seahorse will be happiest. Or don’t keep them at all, as many seahorse keepers discovered they do best only with their own kind. For specific recommendations, see the article on seahorse tankmates.

Because of their unusual shape and behavior, seahorses also need a habitat with a different decor than most marine fish tanks. Wall to wall live rock is not the kind of home your seahorses will appreciate. They aren’t usually found associating with the cliff-like walls of a reef, and are too clumsy to navigate the holes and crevices of live rock piles. Instead, they prefer open space with hitching posts to anchor themselves with their prehensile tail. Hitching posts can be a variety of sizes and shapes. In fact, the more variety, the happier your seahorses will be. As long as its relatively columnar and their tails can wrap around it, your seahorse will be happy. Some common hitching posts include: artificial branching corals, plastic & silk plants, brightly colored poly rope, and macro algae such as caulerpa.

A 30 gallon seahorse and pipefish aquarium

A 30 gallon seahorse and pipefish aquarium

With that being said, no seahorse tank should be devoid of live rock. Live rock is still an important part of the miniature ecosystem you are attempting to create. What is important is balancing the volume of live rock with the open space needed. Tonga branch rock is one way of creating both hitching posts and providing live rock. Most seahorses enjoy other types of live rock to poke around in, looking for naturally occurring crustaceans to eat.

The size and shape of the aquarium is also important to seahorse health. 20 gallons per seahorse is the absolute minimum for a pair of seahorses. 40 gallons per pair of the really large species such as H. ingens or H. abdominalis. However, water volume is only one factor when determining the best size seahorse aquarium. Seahorses need tall aquariums, as they are vertical swimmers. This is especially true if you plan to breed them. Minimum tank size is three times the total adult height of the seahorse. Be sure this is after you subtract the depth of your sand bed. A 20-inch tank with a 6 inch sand bed only gives seahorses 14 inches of usable height.

The last issue concerning the seahorse environment is water quality. Seahorses are messy eaters; consuming large volumes of high protein, high fat foods. They have an inefficient digestive system, which leaves the aquarist with high protein, high fat poops that break down in the aquarium. For this reason, it is important for the seahorse aquarist to watch their water quality closely, and set up their aquarium to deal with these waste-producing machines.

An efficient nutrient export system is a must. Nutrient export is simply put, a method of removing waste, either before it brakes down to nitrate and phosphate, or after. The simplest nutrient export system is large water changes, which physically removes the water with the waste, and replaces it with new water that does not have waste. However, water changes large enough and frequent enough to make a profound effect on nutrient remove are labor intensive and costly. Most aquarist, therefore, supplement regular partial water changes with other methods of nutrient export. Commonly used methods are protein skimming, refugiums and macroalgae for biological export, and nutrient absorbing pads.


Seahorse keepers are obsessed with food. Live food, dead food, big food, small food. Why? Because our seahorses are so dependent on it.

In nature, seahorses spend most of their time eating. This is because their digestive system is very short and not very efficient. They have evolved to be eating machines. Unfortunately, they have evolved to be picky eating machines, only recognizing the movement of live food as actual food. Thus comes the problem many seahorse keepers face. Seahorses not only require frequent feedings of highly nutritious food, they often will only eat living food. Which means for many seahorse aquarists at least one extra tank for food and a fairly large food budget.

Fortunately for aquarists, due to recent laws regarding the control of the number of seahorses traded internationally, captive bred seahorses are popular. Thankfully, they usually are grown on frozen food and have adapted early on to eat whatever is thrown in the aquarium. However, that doesn’t entirely answer the problem of seahorse feeding. Many foods available on the market are not suitable as a staple diet for seahorse. Mysis, a popular frozen food for seahorses, is usually only available from freshwater sources. These sources do not have the right balance of fats appropriate for marine animals, and as a staple diet is likely to result in deficiencies as well as problems with accumulation of fatty tissue in the liver. Brine shrimp is virtually void of nutrition. Small krill, sometimes marketed as plankton, is a great food source, but many seahorses turn their noses up as they do not like the hard shell.

The same problems are encountered with live food. Ghost shrimp are typically freshwater and don’t contain the right nutrition for saltwater fish. Brine shrimp are very poor nutritionally. Saltwater ghost shrimp and mysis are sometimes available but tend to be expensive because they have to be shipped from the cost.

So what is a seahorse keeper to do? Variety is the spice of life. While it may take time to convince your seahorse that mysis isn’t the only thing they want to eat, most that eat frozen will learn to eat other shrimp like frozen food, such as krill. With live food, spend the money to get live saltwater shrimp and supplement. You can also enrich food with various supplements such as Vibrance or Selcon. Feeding live shrimp high quality foods to “gut load” for seahorses is another option.

Feeding should be done at least twice a day. As I said, in the wild they eat constantly. Fortunately for us, we can provide them with a high quality food where they can have a couple square meals a day and not force the aquarist to quit their job to ensure a constant supply of food. However they still need to be feed more often than most fish, and wouldn’t do well missing feedings on a regular basis. It’s also important to feed young seahorses more often, ideally 3-4 times a day as they grow.

For specific information on seahorse food items, see our seahorse food article

Healthy Stock

Perhaps the most important factor in keeping seahorses is starting off with healthy animals. A big problem facing seahorse keepers is how rapidly their condition can decline, especially when you take into account the stress of transportation and acclimation can have seahorses. And unfortunately for aquarists, once their condition starts to decline, it is very hard to turn around. They also seem more susceptible to spreading disease among otherwise healthy individuals once they fall ill.

So what can you do to assure you are starting with healthy animals? The absolute best thing you can do is start with captive bred seahorses. They are by far the superior choice for longevity and health. They have been breed in captive conditions and are therefore acclimated to tank conditions. It is equally important, though, to get your captive bred seahorses from a reputable dealer. You want to be sure that the dealer isn’t mixing them with wild seahorses, and ideally not with wild fish at all. While captive bred seahorses are much healthier individuals, some seem more susceptible to disease carried by wild fish, as they have never been exposed to “normal” pathogens.

It is also important to make sure you are getting true captive bred seahorses, and not tank raised. Tank raised are often raised in a situation where they are exposed to natural, unfiltered seawater and are exposed to a lot of pathogens. Some aren’t trained to frozen foods. Most local fish stores do not know the difference, so be wary of any seahorses unless you know the exact source.

A Healthy Female H. kuda

A Healthy Female H. kuda

If you have to go with wild caught seahorses, then its even more important to be sure you get your seahorses from a reputable dealer. The dealer must understand the specific requirements of seahorses, or you are likely to acquire sickly animals that are unwilling or unable to eat. You also must watch out for disease animals suffering from capture and shipping stress. While it may be tempting to try and “rescue” suffering animals, it will most likely result in disappointment, as well as encourage irresponsible fish stores to carry more seahorses likely to perish.

Purchase checklist:

  • Active, moving around. Contrary to popular belief, seahorses rarely stay in one place and are moving around quite a bit.
  • Bright, active eyes. A healthy seahorse will swivel its eyes around in constant search of food.
  • Full, round belly. A healthy seahorse is a will feed seahorse. While they tend to be fairly thin by nature, any caved in sides is a bad sign.
  • Clear fins.

Things to avoid:

  • Cloudy eyes/dead stare (not much eye movement)
  • Caved in sides, hollow looking plates.
  • White, grey, or inflamed growths. Algae growth is normal, though.
  • Heavy breathing/panting/coughing – Seahorses tend to breath heavier than most fish, though rocking back and forth from breathing so hard, or looking though they’re coughing every few breaths is generally a sign of gill parasites or a seahorse being at death’s door.
  • Bloating. While a fat seahorse is a healthy seahorse, they also succumb to infections that cause fluid to accumulate under the skin. It can be difficult to tell the difference in the early stages, but one thing you can do is watch for if it is still eating or not.

It may not always be possible to observe a seahorse before purchasing considering some of the best sources are online. Which is why it is so important to be sure to choose only a reputable dealer. If you do purchase online, be sure to watch for these traits right after purchase so you can notify the vendor if there are any problems with your newly acquired stock. Some online sources of seahorses.

In addition to picking out healthy individuals, its important to pick species that will thrive in captivity, whether wild caught or captive bred. In general, the species that seem to be best suited to captivity are H. erectus, H. zoestrae, and H. reidi. Captive bred specimens of H. erectus and H. reidi readily eat frozen food. H. zosterae requires live food, but eats easy-to-hatch baby brine shrimp. All are fairly disease resistant. The wild caught specimens of these species tend to do will in captivity also, as long as you’re willing to meet the specific wild caught requirements. H. reidi is difficult to train to frozen food, but as long as you’re willing to feed it live food will thrive. H. erectus learn to eat frozen quickly, but you have to watch for parasites in wild caught individuals. The care for captive bred and wild caught H. zosterae is pretty much the same.

Once you have you’re healthy stock, you need to keep it healthy. This means quarantining. Yes, this includes captive bred individuals, even though many breeders claim it isn’t necessary. While most captive bred animals are in fact disease free, as claimed, you still need to make sure they didn’t pick up any diseases at a distributor, etc . . . Quarantining new animals also gives you a chance to observe their eating habits in a quiet, close environment where they can’t easily disappear into the decorations of the tank, or be out-competed by established tank members. Quarantining should be done for a full 4 weeks in a cycled aquarium, possibly longer in the case of wild caught seahorse. Many people ignore this advice until they lose their first tank to some highly contagious disease – myself included. Learn from our mistakes and ALWAYS quarantine. I cannot emphasis this point enough. Just do it!

While this just a basic overview of what is needed for keeping seahorses, following these three keys will lead to a happy, healthy seahorse tank.

27 Responses to “Keeping Seahorses: Three Keys to Success”

  1. FusedJaw » Articles » 10 Things You Should Know About Keeping Seahorses As Pets. Says:

    […] to coral and anemone stings, and need a different environment to thrive. See our article on keeping seahorses. 5) Seahorses have a specialized diet. Seahorses are picky eaters, and the need to eat a lot. They […]

  2. julie Says:

    i never thought that seahorses could be this delicate to take care of. i loved seahorses, i’ve always have since i was little kid. thanks for this very useful info. i think i still need to study more on how to take care of them before i could get one.

  3. Joel Lopez Says:

    I have a wild caught seahorse from the carribean, west coast of Puerto Rico. I will like to know the sex, age ( young or older) if look healthy and the kind (species) to get a mate for her/his. Can you help me, please?

  4. kristine Says:

    Hello, I was looking for something to read when I found yours, nice blog!! I’ve check the whole stuff and its really interesting. Hope to hear more from you dear writter. Keep it up!

  5. kyrie Says:

    I love to have one but its kind of complicated to maintain them. I was wondering if this seahorse could survive on a tropical type of environment or should I keep them on a place where the temperature would match up under water requirements. This is very useful information to start of. Thanks for the secret.

  6. Emma Says:

    ***PLEASE HELP ME!*** I got a marine tank for christmas this year, and I have to wait 3-4 weeks before I collect my seahorses, however my friend has been telling me that they are almost impossible to keep and that they are very likely to die almost immediatly.. I NEED HELP!!

  7. admin Says:

    No, they are not almost impossible to keep. They do, however, require dedication and commitment to have success with. Is this your first marine tank? If so, I strongly recommend researching how to keep marine fish, that’s going to be the most important thing. I’d also get the book Marine Reef Aquarium Handbook by Dr. Robert Goldstein

    If you’re new to marine aquariums, I’d also suggest waiting a good 4-6 months before you get your seahorses. This will give you time to figure out the basics of marine keeping. You might also want to consider a small goby or two, which are seahorse safe and will give you a chance to figure out what working with seahorses is like. I know 4-6 months seems like a long time to wait, but once you start setting it up and getting ready, time will fly really quickly.

    The best thing I can say is just read everything you can. Seahorses aren’t that difficult but they do have some specific requirements you need to adhere to if you want to be successful.

    Can you also post what the system you got for christmas is like? I.E. how many gallons, what type of filter, what type of light, etc . . . I can take a look and see if it is a good setup for seahorses or if you should make some changes before you get your seahorses.

  8. PETER HICKS Says:

    is a 24″ 24″ 24″ tank,42gallon big enough to keep sea horses?

  9. Aquagrrl Says:

    A 24″ cube is big enough for most species. I’d avoid H. abdominalis and H. ingens, but other species should be okay. The only word of caution I’d give is that if its a all in one unit like a biocube, those tend to get too warm for seahorses.

  10. There's certainly Says:

    I love this web-site! The info is invaluable. Thanks a ton for most of the posts and making my personal day. Thanks, There’s certainly

  11. stephen Says:

    i have tried to take care of seahorses ones but it only lasted for a month and they all died. i think i failed on the feeding process since i’m a very busy person. i never thought that seahorses eats that much maybe that’s the reason why they all died.

  12. christopher Says:

    hi i have a 2 by 1 by 1 tank i am going to fit with a sump system so i can put all the filtration etc in the sump so i cant see it plus the seahorses then cant hang onto anything they shouldnt 😀 will this system be big enough the sump will only be like an 20 by 1 by 1 in dimensions also do i need a protein skimmer i dont have one in my marine tank and seem to do fine without 🙂

  13. Aquagrrl Says:

    A protein skimmer isn’t absolutely required, but it’s a really good idea. Seahorses are more picky about water quality than other fish. Especially disolved organics, which a protein skimmer helps process. Plus they are very messy eaters; they don’t digest their food very well so a lot of nutrients are left in the tank. If you decide not to have a protein skimmer, you’ll need a very efficient nutrient export system – expect to do frequent water changes; weekly at a minimum.

    A lot of people have trouble down the road without a protein skimmer; especially months down the road after unseen waste start to accumulate. I don’t want to say it can’t be done but I’d expect more bad than good to come of skipping the skimmer.

    The tank size you have sounds too small. It sounds like approximately 15 gallons (57 ltr), and you’re going to want a minimum of a 29 gallon (110 ltr) for most species. Unless you’re thinking of keeping dwarf seahorses, which have very different requirements and then the tank would be almost too big.

  14. Victoria Says:

    Hi my fiancee has been keeping marine tanks for almost 2 yrs now and is ready for a seahorse tank. I have a few concerns as they are expensive to buy and keep is a half moon tank okay for them. Its 27 in high. IS the rounded front make a difference for the seahorses? Also where he is keeping the tank its a cooler part of the house even in the summer. If the tank does get too warm is it okay to use something like an air conditioner to get the temp down? He really doesn’t want to buy a chiller for many reasons, but I’m worried the temp might get too high. His 90 gallon never runs above 80 in the summer and its usually around 78 F when we do run an air conditioner, but he has his heater set to 78 so i think it could drop a lot if there was no heater in place. I’m trying to see if it can be done without a chiller. Also if temps do get above 78 is this a death wish for seahorses or is it just playing with death because of them being more susceptible to disease? Your answers are much appreciated TIA.

  15. Aquagrrl Says:

    The rounded front won’t make a difference. Yes, you can use AC to get the temp down. It’s not necessarily a death wish if your tank gets that warm, but problems are more likely to occur. I had one tank of seahorses that was in a room that got too warm on occasion in the summer. Upper 70’s. The first few times it happened everything seemed okay, so I stopped worrying about it. But by the end of summer, both seahorses had gotten sick and died during a warm day. And I repeat, their tank did not get excessively warm, just the upper 70’s.

  16. Andrew Says:

    Hi fellow reefers/seahorse fans,

    I have 2 tanks a 90 gallon FOWLR and a 30 gallon biocube that I have been keeping a pair of H. erectus for the past 6 months (waiting to be a papa). They are so cool and entertaining, and definatly have personalities that make them a jow to watch. I will post when the babies come

  17. Kes Says:

    With regards to purchasing online, I requested a video of the seahorses eating frozen food before I would purchase. It made me feel a whole lot better about sending money over the internet in hopes that healthy seahorses would appear at my house 😉

  18. TamiW Says:

    Patty, you may be able to use natural seawater, but you’ll need to take some precautions. You’ll want to collect it far away from shore, so need a boat. If you have that, then you can collect. You’ll want to sterilize it, bleach is ideal. I hope that helps!

  19. Patty Lemme Says:

    I live right near the Ocean, can I use local seawater?

  20. Mike Holmes Says:

    We are new to the aquarium life and have a ten gallon tank with 2 clown fish. As a gift we were given a seahorse for Christmas. All had been good until earlier this week. He has slowed his activity and eating. From time to time he springs back to an active state and swims around and then he becomes quiet and docile.
    We are worried. We spoke to our local guys and they had us recheck the water. All appears within range but our horse is without question not enjoying his life at this moment.

    Any thoughts?
    Thank you!

  21. TamiW Says:

    A 10 gallon aquarium is far too small for most seahorse species, and clownfish are not good tank mates for seahorses.

  22. Hannah Says:

    Hello! Great article, you seem to know your stuff about seahorses. My aquarium just acquired a wild caught H. ingens species. I have done a sufficient amount of research on how to take care of it however, I am worried for its survival. We have had it for about three days and have tried feeding it some live food (considering it is wild caught, I thought that would best mimic its natural environment) but it has not accepted any live food and has hardly moved. What are your thoughts on this particular species and how to better care for it? Thank you!

  23. Cowbulls Says:

    Let’s imagine the optimum environment for a home seahorse aquarium. What would be included in the way of equipment (what would be the standard dimension tank without the added expense of a custom built tank? ) , live rock and and other items in the tank. Which species of seahorses are considered the hardest?

  24. kayla Says:

    Hi I was wondering when quarenting would you need a seperate tank for each sea horse and can you introduce more than one sea horse at the same time to a tank

  25. Drazic Soska Says:

    Hi I was wondering if the orca nano tank would be suitable to keep sea horses in?

  26. Braxton Teasck Says:

    Hello I was wondering what can be done to help the bio cube not get so hot? I have been looking into a seahorse tank and found the biocube 32 to be suitable and many people seem to use them.

  27. William Moore Says:

    Hi there, I have 9 dwarf seahorses in a 35 gallon bow front. The tank is just for them. The present tank is designed to be very alive. All kinds of pods are free living. Once Tigger Pods get over a certain size they are safe breeders. If brine shrimp get to adult size they can free breed in the tank. The eggs they produce then do not have the usual thick husk. The tank seems to produce all the live food they need. Only a 1 square foot section of wall is kept clear for observing.

    I have tried lots of seahorse setups and the one described below has been the lowest maintenance cost and feeding costs. This Artisian Spring Up flow System also works great with corals and large frags. When I move a frag it has been sitting on fresh oxygenated up flow. There are no dead spots under the gravel, just a clear water dark refugium ( 2 sq ft by 1/2 inch ) . The gravel gets stirred sometimes to drive out live food. There is no toxic cloud.

    Experimental Gravel Up Flow Design ( like a spring fed lake )

    Dual Large Sponge Filters with 5 watt 12 volt pumps that pump into two Reactors on back. All protein and oil is caught by the Foam Cores and they are replaced ( not cleaned ) every month ( $1 each ). Other than the light the two pumps at 10 watts total do all the work. There is no heater.

    Re-purposed Under Gravel Filter Grates with Standpipes going up above the water level. There is about 2 inches of crushed coral gravel over the Grates.

    The return water from the Reactors is dumped down the Standpipes and distributes under the Gravel bed. The reactors need not be packed but are available.

    Brine Shrimp Eggs can be dumped down a stand pipe to hatch in the 1/2 inch high gallery under the Gravel. The hatched shrimp work their way up through the course gravel and leave the husks behind.

    The only current is from two large bubble stones at one end. There are 6 Shell Hives for mysis shrimp. Two porcelain crabs and a lettuce nudibranch. No fish or snails and no true crabs.

    KH 10
    SG 1.024
    Ph 8.1
    Nitrate 20 ( max ) The reactors can be used but this level seems to work
    Temp 73 F
    Light Warm White CFL 2700 ( reduces red slime and brown algae ) No LED’s

    Please comment, my system may be a well known type ( Name? ). I have never seem the like and it works fantastic. It also might be scaled down to a Nano Tank.

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Read previous post:
Example 29 Gallon Seahorse Aquarium – Basic

One issue that new seahorse keepers struggle with is what exactly they need for an aquarium setup to keep seahorses....

Read previous post:
Example 29 Gallon Seahorse Aquarium – Basic

One issue that new seahorse keepers struggle with is what exactly they need for an aquarium setup to keep seahorses....