Quarantine for saltwater fish

Written by

aa sick-fish

Quarantine: reasons, rationale and method.

Why Quarantine?

  1. To allow your fish to become accustomed to captivity in a controlled environment.
  2. To allow treatment of common disease and parasites in a controlled environment.
  3. To reduce the stress of acclimation.
  4. To reduce cost associated with S/W fish keeping by reducing fish mortality.
  5. To allow easy observation of new fish in case of disease.
  6. Reduce the cost of medication.

These are only a few reasons to quarantine your fish. Most local fish stores will do their best not to pass on disease or parasites, but despite their best intentions we sometimes end up with diseased fish. There are certain things we, as customers, can do to lessen the likelihood of problems, but nothing is perfect.

  1. Put a deposit on the fish and allow the store to hold the fish for a week.
  2. Never buy a fish until you have seen it eat.
  3. Look closely for signs of disease and/or parasites.
  4. Look at the other fish in the same holding tank for disease and/or parasites.
  5. Never buy a fish the same day it was received in the store.
  6. Ask the store if they quarantine the fish prior to sale.
  7. Know the fish you have in your tank and the compatibility of the fish you want.
  8. Know the dietary requirements of the proposed fish.
  9. Use proper acclimation procedures.

Set up a basic quarantine system for about $30.00.

Purchase a sponge filter and air pump (filter cost around $8.00 air pump around $6.00). After you find the fish you want, place a deposit on it and begin running the sponge filter in your sump in the display tank for the week prior to picking up your new fish.

Use a 10-gallon tank (can usually purchased for about $10.00), fill with water from the display tank. Put the sponge filter in the 10-gallon tank, and place some sort of decorations in the tank (I use large PVC fittings), to give the fish a place to hide. Use a heater to maintain a stable temp, in a 10g tank I would use a 50W heater, maybe as low as 25W, depending on your climate and the temp of the house. No substrate is used; I do however recommend the use of some sort of lid, even if it is just a piece of plastic (eggcrate works well for this).

Acclimate your fish to the quarantine tank; float the bag for about ? hour, empty the fish and bag water into a bucket, use airline tubing to begin a drip from the quarantine tank to the bucket (tie a loose knot in the tubing to slow the drip), when the bucket has about 4X as much water as it started with net the fish into the quarantine tank. Once the fish is in the tank, it is there for 3 weeks. It is not recommended to quarantine more than one fish at a time. If you must place another fish in the tank during the quarantine period, the quarantine period starts over again.

With the fish in the quarantine tank you can treat preventatively for common parasites or infections. I like to just watch the fish and see if it needs treatment. Whatever you decide, the fish is in a separate tank from the rest of your fish, so it cannot infect the display tank. A good portion of the mortality will be collateral fish loss, fish that were previously healthy but became infected after placing the new fish in the system without quarantine.

Okay, we quarantined the fish and it’s time to put it in the main tank. I do another acclimation to the display tank as described above, and put the fish in a clear plastic container in the main tank. This allows the “old” fish to work out their aggression for their new tank mate without actually being able to harm him. I leave the new fish in the container for 2 days to a week depending on how the other fish react.

Now that the fish is out of quarantine and in the display tank, we tear down the quarantine tank until it is needed again. Simply add a cup of bleach to the quarantine tank and let it run for 1 hour, this should kill any organisms in the tank. At this point; add de-chlorinator, drain the tank and allow all parts to air dry, put away until needed again. Some people choose to leave their system running all the time, I do not, and the reason is that if the quarantine tank is not set-up, it prevents me from impulse buying a fish that I should not buy. This is a pretty good quarantine system and has saved me a lot of money on fish! I personally use a 20L instead of a 10-gallon, but a 10 will work as well. Quarantine is probably one of the single most responsible things we as fish keepers can do for our fish.

Should you have any questions or comments about this article please feel free to post in the Saltwater & Reef – General Discussion forum.

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