quarantine tank

Quarantine Tank for Saltwater Fish

One of the best things you can do to help maintain a healthy saltwater aquarium is to set-up and use a QT, or quarantine tank for your saltwater fish.

What is a QT?

As mentioned above, QT is an abbreviation for the term quarantine tank, which sounds a bit like something you would see on a zombie apocalypse show, like Walking Dead (which I love, by the way), but the premise is surprisingly similar.

To prevent the spread of the zombie virus, you would put new arrivals to your post-apocalyptic headquarters in quarantine before you allowed them into your camp in order to ensure they aren’t infected. Once inside your camp, they could spread the zombie virus to the rest of you–and that would not be good.

Well, the stakes aren’t quite that high with a saltwater aquarium but prevent the spread of infections and parasites in a saltwater tank, you set up a QT to ensure that the new arrivals don’t infect the rest of your tank with something (probably NOT zombie virus) that they’re carrying.

A QT is a separate, relatively bare tank that is dedicated to housing newly purchased fish for an intermediate period of time.  Any of the fish that you purchase could be harboring parasites or a pathogenic disease.  The only way to prevent the new editions from infecting those fish in your display tank is to quarantine them in a QT until you are certain they are parasite and disease free.

When I first converted from a freshwater tank to a saltwater tank, I was a bit cavalier and downplayed the importance of quarantine. My freshwater fish tank had its share of ich and other infections, but the range of medications available usually did the trick–and even if they didn’t–it was relatively easy and inexpensive to just reboot the tank and start again.

With a saltwater tank, rebooting is not as clean, not as easy and certainly is much, much more expensive. QT is especially important if you plan to have live rock, coral or invertebrates in your display tank, because any of the treatments you would use if your tank became infected, would kill off the beneficial invertebrates you paid good money for.

Once a parasitic infection gets into your display tank, it can be challenging to get rid of.

What does a QT do?

The QT, once you set up and use it, actually serves multiple functions.  It provides a:

  • A physical barrier between your new fish and the display tank, preventing contamination in the first place
  • A way for you to closely observe and monitor the behavior of the new saltwater fish out in the open (most newly introduced saltwater fish will hide in the live rock aquascape or other ‘structure’ in your aquarium and only come out once they reach a minimum comfort level—which varies by species and individual)
  • A way for you to safely treat and remove any threats without the risk of harming any of your other livestock
  • ‘Recovery place’ for your newly purchased saltwater fish to eat, gain strength, and recover from the stresses of shipping and pet store display—and get ready to compete for food and shelter with the other saltwater fish in your reef tank.
quarantine tank

By Andrzej 22 (Own work) [CC0], via Wikimedia Commons

Unfortunately, if you’re like me, you may have received advice like this when you decided to get into the saltwater aquarium hobby, and you may have rationalized away the need for a QT.

If you are like me, you probably had a healthy, stable reef tank running for several months and then suffered a catastrophic loss as saltwater ich, amylodium or some other parasite reached plague proportions in your saltwater aquarium and you suffered major losses to your saltwater fish tank.

Adding fish to a tank without the proper quarantine period is like playing Russian Roulette with your fish tank.  You can get away with it for a few rounds, but after a while, the odds of beating the odds stack up against you, and your fish will pay the price. Let me assure you, next to the protein skimmer, the QT is one of the most important pieces of equipment you can purchase.

The trouble and expense to set it up pales in comparison to replacing your saltwater fish, coral and other invertebrates, catching any survivors, breaking down the tank and setting up the QT anyway.  Save yourself the life lesson I learned the hard way and spend the money to set up the QT.

Have a sick fish?

Another great reason to keep a QT running is that you can remove any sick or injured fish to your QT as a safe haven to recover and be treated for whatever is ailing them. Treating a sick fish while in isolation is often vital to bringing the fish back to health, and QT tank is a great place to do that.

In this instance, you may hear someone refer to this as a hospital tank, not a QT, but it is essentially the same thing. A QT is an isolation tank to prevent the introduction of parasites or infection into your display tank, a hospital tank is an isolation tank where you treat an infected or injured fish. Learn about aquarium antibiotics and other treatments here.

For more information about quarantine tanks

Check out one of these other pages:

The importance of a quarantine tank

An Ounce of Prevention…

Have you suffered any losses like I did, because you didn’t utilize a quarantine tank properly? Leave a comment here with your story so that others don’t repeat the same mistake we did.

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