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How to acclimate and quarantine new seahorses!

Setting up your very first seahorse tank is such a magical experience.  Typically it starts with seeing another hobbyists amazing seahorse tank, and realizing that more and more people are successfully keeping seahorses that are captive bred for the hobby.  The idea has been planted in your mind, and now you can see how perfectly a seahorse tank will look in that specific spot entering your front room.  You imagine the flowing gorgonians and dancing seahorses greeting you every time you get home, and how much you would enjoy seeing such a magical creature before you leave each day.

The image returns to your thoughts every time you pass the spot, convincing you more each time that this is an achievable task.  You begin to look for information online, and stumble across a silly girl who whispers to seahorses (wink).  Once you realize that setting up a seahorse tank is something you really want to do, you dive head first into learning about their care and how to properly set up the tank.  After taking the time to set up correctly, you return home one day and realize that your dream has been fulfilled, and your tank is ready for seahorses!

After all the research, planning, decisions and actual work that you put into just getting the tank ready, waiting even longer to enjoy your lovely seahorses is not fun.  However, making sure that the seahorses are healthy and eating well before introducing them to your tank can help you avoid a lot of extra problems that might destroy your beautiful vision.  Choosing the best seahorse for your tank are covered in my other articles: Which species is best for beginners? and more help can be found in the Beginner’s Corner.   But, lets review some of the proper acclimation and quarantine practices that will help your seahorses thrive in their new homes:


There are 2 main techniques used to acclimate a fish to a new tank.  The method chosen depends on whether the fish was shipped or picked up locally, but your best bet is to follow the instructions of the seller:

  1.  Drip acclimation – involves using an airline, diy drip kit, or an acclimation kit purchased online to slowly add tank water to the water in the container that the fish was shipped in.  The idea is that the fish is slowly acclimated to the new water, to avoid shock from any differences in water parameters.  This works well in a local situation, or if you have a fish that is extremely sensitive to fluctuations in parameters.  However, we now know that there are processes going on in the water during shipping which can make a long drip acclimation harmful to the fish.  The level of harm depends on the length of shipping time.  A basic explanation is that any ammonia that was created during shipping is non toxic, because the co2 in the bag lowers the ph of the water (converting ammonia into ammonium).  However, the moment the bag is opened, and air hits the water and co2 is released, the ph rises and the ammonium converts back to ammonia.  The fish is all of a sudden in a bad situation.
  2. Temperature acclimation – As more has been learned about water during shipping, many have realized that the most important aspect is ensuring that the temperature between the water in the bag and water in the tank are not extremely different.  The basic guideline is to make sure the temperature difference is not more than 4-5 points different between bag and tank water.  This method involves leaving the UNOPENED bag floating in the tank for 15-20 minutes, so that the bag water has time to slowly reach the same temperature as the tank water.  Once the water temps match based on time and “feel”, the bag is opened and the fish is immediately put into the tank.  *If the shipping water is extremely cold or hot when received, allow the container to reach room temperature before floating it in the tank.

In a shipping situation, acclimation instructions are typically included in the box.  Your best bet is to follow them.  In fact, you should always follow the instructions of the person selling the fish.  Not only does this ensure that any guarantees are honored, but the seller might want things done a certain way because of their own shipping methods.  The levels and type of oxygen, any additives, and many other things can change how acclimation should be handled.  If you choose to use a different method than instructed by the seller, you might make things worse on the fish.  Rather than take chances with your new seahorses, just follow the enclosed or online instructions.



As with all things, there are also different quarantine methods:

  1.  Observation quarantine:  involves keeping new seahorses (and everything else) in a very simple tank to observe them and get them eating properly before adding them to the display tank.  Putting a new seahorse in a very boring glass tank with a few hitches might even seem “mean” to some people, but the truth is……it can help them adjust after shipping.  You have to consider the following:
    • Captive bred seahorses from a breeder are coming from a very sterile, simple setting.  Whether the breeder uses tubs or glass, the seahorses are not used to rock, sand, other fish, and/or human faces staring at them while they try to eat.  So, no matter what you try to do to make them feel “at home”, there will be an adjustment time.  Letting them get used to you, and the parameters you keep, by putting them in a tank similar to the breeders….will help.
    • Time to observe the seahorses will allow you to deal with any hitchhikers, problems with the seahorses or anything else before you add them to the tank you spent so much time setting up!  As long as there are no fish the the QT, many parasite life cycles will die off, many hitchhikers will show their ugly faces, and you can treat seahorses without ruining your tank’s “cycle”.
    • The observation method is much better than nothing when it comes to keeping the tank free of problems.
  2. Profilactic quarantine – involves using medications to treat new seahorses in a preventative fashion.  Basically, this method is used by more experienced hobbyists, breeders and vendors to condition wild caught fish for the problems that almost always come when taking fish from the ocean.  While I personally think that hobbyists should always buy captive bred seahorses, there are a lot of vendors still selling seahorses raised in natural salt water, or in conditions that expose them to wild caught fish.  So, if you buy a seahorses that you are not sure are truly raised in sterile breeding situations, you may want to use a quarantine to de-worm the seahorses, and treat for any parasites and/or bacterial issues before they can become a problem.
    • There are way too many treatments to cover, so I will merely say that a hobbyist should ask a professional before using medications.

Because this article is aimed at new seahorse keepers, we’ll concentrate on the observation quarantine.  Medications might eventually play a part, if you notice that the seahorse is having a problem.  But, using a simple observation quarantine for anything and everything you add to the tank will save you so much heartbreak.  So many times I have been asked for help because a seahorse was stung by aptasia or a bristleworm.  Or witnessed all the work involved in allowing a tank to sit fallow for months to kill off a parasite.  While the observation QT will not prevent ALL problems, it can at least allow you to get the seahorse eating properly, and realize any problems prior to infecting the display.

Everything that has to do with a reef and/or seahorse does require patience.  You can fulfill that dream tank in that corner of your living room successfully, but taking the time to do things correctly will mean you never have to spend MORE time staring at an empty tank, while you treat problems in a hospital tank.