Here is a picture of our coral quarantine tank

How To Setup A Coral Quarantine Tank

by Justin Hester

When keeping a reef tank in your home, there are many variables that have to be managed. Lots and lots to be exact.  One variable that can be managed almost entirely yet is still the downfall of many an aquarium and causes the exit of many people from the reef keeping hobby are coral pests.  It is very easy to buy a coral, bring it home, and just add it to your aquarium.  The dark side to doing that is that what you put in your tank typically introduces many unattended guests.  Think of it like Vegas, if you play this game long enough you are guaranteed to lose.  The silver lining here is that with a little effort and some tank parts you probably have laying around, you can avoid adding pests to your tank altogether.

Here at ReefNation we are no exception to this rule. Over the years we have seen our fair share of pests which like most has resulted in breaking down systems,  doing weeks of dips, and in some cases even having to toss coral colonies.  Our teams’ combined 30+ years of working with marine tanks has resulted in some quarantine techniques and treatments that work really well when implemented in a big or small reef tank.  Our hope is that some of this info will help others deal with or better yet prevent the introduction of unwanted coral pests to your reef tank.


What Is A Quarantine Tank?

Simply put, a quarantine tank is a place that corals can be put into before they enter into your main display system.   The idea is to create a buffer zone where you can identify and treat any of the pests that can come in on new frags or maricultured corals.  These pests can range from unwanted crabs to montipora nudibranchs or even worse acropora eating flatworms that can all eat your corals.


Zooanthid Coral ReefNation

How To Build A Quarantine Tank

Typically a quarantine tank is a small, simple version of your main tank that meets all the minimum survival criteria for corals to have a 1-3 month stay in.

The setup we like to use at ReefNation includes:
-5-20 gallon tank  ( or what you have sitting around)
-decent lighting to keep your corals alive and growing.  T5, MH, or small LED work fine
-power head and or small protein skimmer to keep water flow adequete

-snails or small tang to keep algae in check

In our setup, we don’t use a protein skimmer currently as we tank tank water from our main display and add it to our quarantine during our weekly water changes. This keeps your costs down and makes it easier to replicate conditions in your QT tank that match your main tank.


How Does The Quarantine Tank Remove Pests?

When corals are in your QT tank, its now time to stare at them.  Seriously, looking at regions where coral tissue meets a frag plug or mount is a great way to spot all sorts of nasty critters that you can then remove via a coral dip.  Through a whole lot of staring over the years, we have seen 90+%  of pests focus their egg laying right in this region.  For this reason, one of our first steps when we get a new coral is to chop off the frag plug or mount plus about a half inch of coral tissue.  It seems like a silly step, but this ensures that eggs are removed most times and thus can shorten your QT process immensely.

We find that it is best to do dips and chemical treatments outside of the quarantine so that there is no chance for those chemicals to affect the biological filter of the quarantine.  The same things that kill the coral pests can really do a number on you good bacteria and we have seen quarantine tanks do a complete cycle as the result of medications.

Sometimes pests can be dealt with IN the quarantine tank  by using natural predators such as wrasse. While nice in theory, this method should be done cautiously as this route will usually leave behind eggs or juvenile pests.  Natural predators are great at keeping a pest at bay, but medications are unfortunately necessary to eliminate them entirely.
The regimen we follow at ReefNation currently involves both a dip and chopping of the plug when corals arrive prior to entry in the quarantine tank.  We like to use Coral Rx or a Bayer dip for this purpose, the later requiring  gloves and a second or third dipping vessel to clean off the dip before return to the QT tank.  We then trim off the frag plug plus about a quarter inch of the coral to make sure that no eggs are added to the quarantine tank.  This last step we just added about a year ago when we saw some AEFW eggs on a maricultured coral we got in.

If  possible, corals should then be placed in the quarantine tank for a solid 4-8 weeks and be observed regularly.  If any nudi’s or AEFW are discovered, start another 8 week timeline and dip corals weekly in order to kill all the new hatch-lings before they can lay new eggs.

This QT process does delay adding crazy corals to our main display or grow out system, but the risk of losing many more corals makes it totally worth it.  Anyone can google AEFW or Monti nudi and read some of the horror stories and years some people have spent fighting these pests once they enter your tank system.  A little effort can result in a beautiful display tank that exhibits growth for years to come.